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Sample records for ce entrained fuel process

  1. Entrainment.

    ERIC Educational Resources Information Center

    Carrier, Romance F.

    1978-01-01

    Presents a literature review including: (1) theoretical studies concerned with the development of methdology to determine the significance of entrainment effects to whale populations and ecosystems; and (2) site and laboratory studies. A list of 107 references drawn from the 1976 and 1977 literature is also presented. (HM)

  2. MODELING AND DESIGN FOR A DIRECT CARBON FUEL CELL WITH ENTRAINED FUEL AND OXIDIZER

    SciTech Connect

    Alan A. Kornhauser; Ritesh Agarwal

    2005-04-01

    The novel molten carbonate fuel cell design described in this report uses porous bed electrodes. Molten carbonate, with carbon fuel particles and oxidizer entrained, is circulated through the electrodes. Carbon may be reacted directly, without gasification, in a molten carbonate fuel cell. The cathode reaction is 2CO{sub 2} + O{sub 2} 4e{sup -} {yields} 2CO{sub 3}{sup =}, while the anode reaction can be either C + 2CO{sub 3}{sup =} {yields} 3CO{sub 2} + 4e{sup -} or 2C + CO{sub 3}{sup =} {yields} 3CO + 2e{sup -}. The direct carbon fuel cell has an advantage over fuel cells using coal-derived synthesis gas in that it provides better overall efficiency and reduces equipment requirements. Also, the liquid electrolyte provides a means for transporting the solid carbon. The porous bed cell makes use of this carbon transport ability of the molten salt electrolyte. A one-dimensional model has been developed for predicting the performance of this cell. For the cathode, dependent variables are superficial O{sub 2} and CO{sub 2} fluxes in the gas phase, superficial O{sub 2} and CO{sub 2} fluxes in the liquid phase, superficial current density through the electrolyte, and electrolyte potential. The variables are related by correlations, from the literature, for gas-liquid mass transfer, liquid-solid mass transfer, cathode current density, electrode overpotential, and resistivity of a liquid with entrained gas. For the anode, dependent variables are superficial CO{sub 2} flux in the gas phase, superficial CO{sub 2} flux in the liquid phase, superficial C flux, superficial current density through the electrolyte, and electrolyte potential. The same types of correlations relate the variables as in the cathode, with the addition of a correlation for resistivity of a fluidized bed. CO production is not considered, and axial dispersion is neglected. The model shows behavior typical of porous bed electrodes used in electrochemical processes. Efficiency is comparable to that of

  3. Problems with the process partitioning theory of stratocumulus entrainment

    NASA Technical Reports Server (NTRS)

    Randall, D. A.

    1984-01-01

    Three different approaches to partitioning were proposed. Ball (1960), Lilly (1968), and Deardorff et al. (1969, 1974) considered the sign of the net buoyancy flux at each level. If the net flux is positive, it is counted as TKE producing; otherwise, it is counted as TKE consuming. This approach can be called Eulerian partitioning. The second approach can be called process partitioning. It is assumed that the various processes acting in concert each produce and consume the same energy as if they acted independently (Manins and Turner, 1978). The total rates of TKE production and consumption are obtained by summing the effects of all the forcing processes. The third approach is Lagrangian partitioning. Each air parcel is considered as either producing or consuming TKE, according to the sign of the product of its density and vertical velocity anomalies. Stage and Businger (1981a,b) have applied process partitioning to the cloud topped mixed layer. One of the most important processes influencing entrainment into such a layer is cloud top radiative cooling. The production and consumption due to entrainment and radiative cooling are thus closely related. Model results are sensitive to the choice of formulation.

  4. The Macroscopic Entrainment Processes of Simulated Cumulus Ensemble. Part II: Testing the Entraining-Plume Model.

    NASA Astrophysics Data System (ADS)

    Lin, Chichung; Arakawa, Akio

    1997-04-01

    According to Part I of this paper, it seems that ignoring the contribution from descendent cloud air in a cloud model for cumulus parameterization (CMCP), such as the spectral cumulus ensemble model in the Arakawa-Schubert parameterization, is an acceptable simplification for tropical deep convection. Since each subensemble in the spectral cumulus ensemble model is formally analogous to an entraining plume, the latter is examined using the simulated data from a cloud-resolving model (CRM). The authors first follow the analysis procedure of Warner. With the data from a nonprecipitating experiment, the authors show that the entraining-plume model cannot simultaneously predict the mean liquid water profile and cloud top height of the clouds simulated by the CRM. However, the mean properties of active elements of clouds, which are characterized by strong updrafts, can be described by an entraining plume of similar top height.With the data from a precipitating experiment, the authors examine the spectral cumulus ensemble model using the Paluch diagram. It is found that the spectral cumulus ensemble model appears adequate if different types of clouds in the spectrum are interpreted as subcloud elements with different entrainment characteristics. The resolved internal structure of clouds can thus be viewed as a manifestation of a cloud spectrum. To further investigate whether the fractional rate of entrainment is an appropriate parameter for characterizing cloud types in the spectral cumulus ensemble model, the authors stratify the simulated saturated updrafts (subcloud elements) into different types according to their eventual heights and calculate the cloud mass flux and mean moist static energy for each type. Entrainment characteristics are then inferred through the cloud mass flux and in-cloud moist static energy. It is found that different types of subcloud elements have distinguishable thermodynamic properties and entrainment characteristics. However, for each cloud

  5. Entrainment and mixing processes in downslope gravity currents.

    NASA Astrophysics Data System (ADS)

    Shishova, Anna; Gritsenko, Vladimir

    2010-05-01

    Downslope density currents play a significant role in vertical water exchange in near-shore zones of lakes, seas and oceans. Entrainment and mixing processes at the density currents' interface has been described by many authors (e.g., Barenblatt, Benjamin, Britter & Linden, Simpson, Turner, Holyer & Huppert, Baines), however further understanding is still required. Main objective of the present work is the analysis of mixing processes, associated with density current propagating along the bottom, based on examination of simulated flows. The simulations were carried out by using a non-linear two-dimensional XZ-model, which solves the following system of equations: D?/Dt = (g/ρ0) (δσ/δz) + νT??; ?φ = ?; Dρ/Dt = kT?ρ; Dc/Dt = kT?c, where ? - is the flow vorticity, φ - stream function, g=982 cm/s2, ρ0=1 g/cm3 - fresh water density, ρ - saline water density, x, z - horizontal and vertical coordinates, respectively; t - time; D/Dt = δ/δt + uδ/δx + wδ/δz; ? = δ2/δx2 + δ2/δz2; νT = ν0 + c×νeff, kT = 0.5νT - turbulent diffusivity and viscosity coefficients, νeff = √Re×ν 0; Re = u0×h0/ν0; ν0 = 0.015 cm2/s; ν eff = 0 at t=0; c=c(x, z, t), 0.0≤c≤1.0 - dimensionless concentration of tracer of the bottom current water mass. For description and comprehension of specific features of mixing processes in downslope currents the approach suggested by Baines (J. Fluid Mech. 2001, vol. 443) is used, based upon employing local parameters and local averaging. Following Baines, four dimensionless parameters were chosen for the description of the basic flow: slope angle ?, Richardson number Ri = g'd3cosq/Q2, Reynolds number Re = Q/ν and M = Q/(g'D3)0,5= QN3/g'2 - the ambient fluid stratification coefficient; here, ν - kinematical viscosity, d - average thickness of the downflow. Two important additional parameters were defined: N - buoyancy frequency, and an associated parameter D - the depth below the source where the initial density of the fluid in

  6. Process for coal liquefaction by separation of entrained gases from slurry exiting staged dissolvers

    DOEpatents

    Givens, Edwin N.; Ying, David H. S.

    1983-01-01

    There is described an improved liquefaction process by which coal is converted to a low ash and low sulfur carbonaceous material that can be used as a fuel in an environmentally acceptable manner without costly gas scrubbing equipment. In the process, coal is slurried with a solvent, passed through a preheater and at least two dissolvers in series in the presence of hydrogen-rich gases at elevated temperatures and pressures. Solids, including mineral ash and unconverted coal macerals are separated from the condensed dissolver effluent. In accordance with the improved process, fresh hydrogen is fed to each dissolver and the entrained gas from each dissolver is separated from the slurry phase and removed from the reactor system before the condensed phase is passed to the next dissolver in the series. In accordance with another process, the feeds to the dissolvers are such that the top of each downstream dissolver is used as a gas-liquid separator.

  7. Development of an entrained flow gasifier model for process optimization study

    SciTech Connect

    Biagini, E.; Bardi, A.; Pannocchia, G.; Tognotti, L.

    2009-10-15

    Coal gasification is a versatile process to convert a solid fuel in syngas, which can be further converted and separated in hydrogen, which is a valuable and environmentally acceptable energy carrier. Different technologies (fixed beds, fluidized beds, entrained flow reactors) are used, operating under different conditions of temperature, pressure, and residence time. Process studies should be performed for defining the best plant configurations and operating conditions. Although 'gasification models' can be found in the literature simulating equilibrium reactors, a more detailed approach is required for process analysis and optimization procedures. In this work, a gasifier model is developed by using AspenPlus as a tool to be implemented in a comprehensive process model for the production of hydrogen via coal gasification. It is developed as a multizonal model by interconnecting each step of gasification (preheating, devolatilization, combustion, gasification, quench) according to the reactor configuration, that is in entrained flow reactor. The model removes the hypothesis of equilibrium by introducing the kinetics of all steps and solves the heat balance by relating the gasification temperature to the operating conditions. The model allows to predict the syngas composition as well as quantity the heat recovery (for calculating the plant efficiency), 'byproducts', and residual char. Finally, in view of future works, the development of a 'gasifier model' instead of a 'gasification model' will allow different reactor configurations to be compared.

  8. The Role of High-Level Processes for Oscillatory Phase Entrainment to Speech Sound

    PubMed Central

    Zoefel, Benedikt; VanRullen, Rufin

    2015-01-01

    Constantly bombarded with input, the brain has the need to filter out relevant information while ignoring the irrelevant rest. A powerful tool may be represented by neural oscillations which entrain their high-excitability phase to important input while their low-excitability phase attenuates irrelevant information. Indeed, the alignment between brain oscillations and speech improves intelligibility and helps dissociating speakers during a “cocktail party”. Although well-investigated, the contribution of low- and high-level processes to phase entrainment to speech sound has only recently begun to be understood. Here, we review those findings, and concentrate on three main results: (1) Phase entrainment to speech sound is modulated by attention or predictions, likely supported by top-down signals and indicating higher-level processes involved in the brain’s adjustment to speech. (2) As phase entrainment to speech can be observed without systematic fluctuations in sound amplitude or spectral content, it does not only reflect a passive steady-state “ringing” of the cochlea, but entails a higher-level process. (3) The role of intelligibility for phase entrainment is debated. Recent results suggest that intelligibility modulates the behavioral consequences of entrainment, rather than directly affecting the strength of entrainment in auditory regions. We conclude that phase entrainment to speech reflects a sophisticated mechanism: several high-level processes interact to optimally align neural oscillations with predicted events of high relevance, even when they are hidden in a continuous stream of background noise. PMID:26696863

  9. The Role of High-Level Processes for Oscillatory Phase Entrainment to Speech Sound.

    PubMed

    Zoefel, Benedikt; VanRullen, Rufin

    2015-01-01

    Constantly bombarded with input, the brain has the need to filter out relevant information while ignoring the irrelevant rest. A powerful tool may be represented by neural oscillations which entrain their high-excitability phase to important input while their low-excitability phase attenuates irrelevant information. Indeed, the alignment between brain oscillations and speech improves intelligibility and helps dissociating speakers during a "cocktail party". Although well-investigated, the contribution of low- and high-level processes to phase entrainment to speech sound has only recently begun to be understood. Here, we review those findings, and concentrate on three main results: (1) Phase entrainment to speech sound is modulated by attention or predictions, likely supported by top-down signals and indicating higher-level processes involved in the brain's adjustment to speech. (2) As phase entrainment to speech can be observed without systematic fluctuations in sound amplitude or spectral content, it does not only reflect a passive steady-state "ringing" of the cochlea, but entails a higher-level process. (3) The role of intelligibility for phase entrainment is debated. Recent results suggest that intelligibility modulates the behavioral consequences of entrainment, rather than directly affecting the strength of entrainment in auditory regions. We conclude that phase entrainment to speech reflects a sophisticated mechanism: several high-level processes interact to optimally align neural oscillations with predicted events of high relevance, even when they are hidden in a continuous stream of background noise. PMID:26696863

  10. Research on the pyrolysis of hardwood in an entrained bed process development unit

    SciTech Connect

    Kovac, R.J.; Gorton, C.W.; Knight, J.A.; Newman, C.J.; O'Neil, D.J. . Research Inst.)

    1991-08-01

    An atmospheric flash pyrolysis process, the Georgia Tech Entrained Flow Pyrolysis Process, for the production of liquid biofuels from oak hardwood is described. The development of the process began with bench-scale studies and a conceptual design in the 1978--1981 timeframe. Its development and successful demonstration through research on the pyrolysis of hardwood in an entrained bed process development unit (PDU), in the period of 1982--1989, is presented. Oil yields (dry basis) up to 60% were achieved in the 1.5 ton-per-day PDU, far exceeding the initial target/forecast of 40% oil yields. Experimental data, based on over forty runs under steady-state conditions, supported by material and energy balances of near-100% closures, have been used to establish a process model which indicates that oil yields well in excess of 60% (dry basis) can be achieved in a commercial reactor. Experimental results demonstrate a gross product thermal efficiency of 94% and a net product thermal efficiency of 72% or more; the highest values yet achieved with a large-scale biomass liquefaction process. A conceptual manufacturing process and an economic analysis for liquid biofuel production at 60% oil yield from a 200-TPD commercial plant is reported. The plant appears to be profitable at contemporary fuel costs of $21/barrel oil-equivalent. Total capital investment is estimated at under $2.5 million. A rate-of-return on investment of 39.4% and a pay-out period of 2.1 years has been estimated. The manufacturing cost of the combustible pyrolysis oil is $2.70 per gigajoule. 20 figs., 87 tabs.

  11. Flame deformation and entrainment associated with an isothermal transverse fuel jet

    NASA Technical Reports Server (NTRS)

    Jenkins, D. W.; Karagozian, A. R.

    1992-01-01

    This paper describes an analytical model of an incompressible, isothermal reacting jet in crossflow. The model represents the flow in the jet cross-section by a counter rotating vortex pair, a flow structure that has been observed to dominate the jet behavior. The reaction surface surrounding the fuel jet is represented as a composite of strained diffusion flames that are stretched and deformed by the vortex pair flow. The results shed new light on the interaction between the vortex pair circulation and flame structure evolution and their relation to the concept of entrainment.

  12. Foaming and Antifoaming and Gas Entrainment in Radioactive Waste Preteatment and Immobilization Processes

    SciTech Connect

    Wasan, Darsh T.; Nikolov, Alex

    2005-06-01

    The objectives of this research effort are to develop a fundamental understanding of the physico-chemical mechanisms that produce foaming and air entrainment in the DOE High Level (HLW) and Low Activity (LAW) radioactive waste separation and immobilization processes, and to develop and test advanced antifoam/defoaming/rheology modifier agents. Antifoams/rheology modifiers developed from this research will be tested using non-radioactive simulants of the radioactive wastes obtained from Hanford and the Savannah River Site (SRS).

  13. ENTRAINMENT MODELS

    EPA Science Inventory

    This presentation presented information on entrainment models. Entrainment models use entrainment hypotheses to express the continuity equation. The advantage is that plume boundaries are known. A major disadvantage is that the problems that can be solved are rather simple. The ...

  14. Entrainment process at the base of the upper ocean layer in an upwelling filament area

    NASA Astrophysics Data System (ADS)

    Estrada-Allis, Sheila; Rodríguez-Santana, Ángel

    2014-05-01

    Entrainment is responsible for the deepening of the mixed layer and controls the transport of momentum, heat, salinity and nutrients across the interface between the turbulent mixed layer and non-turbulent layer below. This process, which is not yet well understood, can be mechanically forced by wind stirring and buoyancy forced through vertical heat fluxes. In strongly dynamical areas such as eastern boundary upwelling systems and their associated filaments, entrainment rates can also be influenced by vertical shear at the base of the mixed layer that may results from advected baroclinic instabilities. We investigate these processes in the Northwest African upwelling region and Cape Ghir filament using CTD, XBT, ADCP, a meteorological station on board for the wind data and heat flux measurements taken during October 2010, as well as one of the first microturbulent profile (TurboMAP) measurements taken in this area in order to obtain the TKE dissipation rate. We find that buoyancy production dominates over the wind induced mixing in the mixed layer of this region as indicate the Monin Obukhov length scale. To determine entrainment rates we compare four parameterizations based on the turbulent kinetic energy (TKE) balance and one based on the relation of the bulk Richardson number. Although there is no clear consensus between these four parameterizations, they provide evidence that vertical shear at the base of the mixed layer acts to enhance the entrainment rate, especially at stations effected by the upwelling filament or mesoscalar structures. We further compare the measured TKE dissipation rates to those parameterized of Gaspar (1988) and Deardorff (1983). Moreover, some relevant aspect relative to the study of turbulent process in the upper ocean layer, such as the choice of an algorithm or criteria to find the mixed layer depth and the difference between mixing and mixed layer are addressed. This work was funded by Spanish Government (PROMECA: CTM2008

  15. Subtask 3.16 - Low-Cost Coal-Water Fuel for Entrained-Flow Gasification

    SciTech Connect

    Anderson, C.M.

    1997-10-01

    The specific objective of this research project is to assess the potential process efficiency and pollution control benefits that may occur by applying the hydrothermal, or hot water-drying, process to low-rank coals as related to entrained-flow gasification systems. Project emphasis is on identifying more efficient coal dewatering and CWF formulation methods prior to gasification. A favorable estimate of incremental cost for integrated hydrothermal drying depends, in part, on increasing the particle size of the feed coal from minus 100 to minus 28 mesh for the purpose of simplifying the slurry concentration process. Two options will be reviewed for dewatering or concentrating the processed slurry: (1) repressurization and then concentration with sieve bends or (2) partial dewatering at system pressure with hydroclones. Both have their own merits, sieve bends being a low-cost alternative, while hydroclone application would not require additional pumping sections prior to gasification. Various CWF samples with different particle-size distributions and solids concentrations will be sent to equipment vendors for application review. Also, EERC cost models will be used to calculate the integral cost of adding the partial dewatering to the hydrothermal technology for a commercial-size facility.

  16. Exploring Stratocumulus Cloud-Top Entrainment Processes and Parameterizations Using Doppler Cloud Radar Observations

    NASA Astrophysics Data System (ADS)

    Albrecht, B. A.; Fang, M.

    2012-12-01

    define vertical velocity variance for one-hour periods. These quantities are then used to examine the terms in the TKE budget in this layer. It is found for the 14 hours of observations used in this study that the variance term is strongly correlated to the dissipation rates in the entrainment zone. However, the ratio of the variance term to the dissipation rate term is 0.12 during the day and 0.06 at night. This difference indicates that the length scales involved in the turbulence and entrainment processes may depend on whether the turbulence is forced by the surface fluxes or cloud-top cooling. To further explore this possibility, the relationships among the convective velocity scales, the vertical velocity variances, and the dissipation rates are examined and compared with entrainment rates from parameterizations based on the convective velocity scale and the strength of the inversion.

  17. A time-variant processing approach for the analysis of alpha and gamma MEG oscillations during flicker stimulus generated entrainment.

    PubMed

    Wacker, Matthias; Galicki, Miroslav; Putsche, Peter; Milde, Thomas; Schwab, Karin; Haueisen, Jens; Ligges, Carolin; Witte, Herbert

    2011-11-01

    Repetitive flicker stimulation (photic driving) offers the possibility to study the properties and coupling characteristics of stimulation-sensitive neuronal oscillators by means of the MEG/EEG analysis. With flicker frequencies in the region of the individual alpha band frequency, the dynamics of the entrainment process of the alpha oscillation, as well as the dynamics of the accompanying gamma oscillations and the coupling between the oscillations, are investigated by means of an appropriate combination of time-variant analysis methods. The Hilbert and the Gabor transformation reveal time-variant properties (frequency entrainment, phase locking, and n:m synchronization) of the entrainment process in the whole frequency range. Additionally, time-variant partial directed coherence is applied to identify ocular saccadic interferences and to study the directed information transfer between the recording sites of the simultaneously derived MEG/EEG data during the entrainment. The MEG data is the focus of this methodological study as the entrainment effects of the alpha oscillation are stronger in MEG than in the EEG. The occipital brain region (visual cortex) was mainly investigated and the dynamics of the alpha entrainment quantified. It can be shown that at the beginning of this entrainment, a transient, strongly phase-locked "40-Hz" gamma oscillation occurs. PMID:21712153

  18. Final Report - "Foaming and Antifoaming and Gas Entrainment in Radioactive Waste Pretreatment and Immobilization Processes"

    SciTech Connect

    Wasan, Darsh T.

    2007-10-09

    The Savannah River Site (SRS) and Hanford site are in the process of stabilizing millions of gallons of radioactive waste slurries remaining from production of nuclear materials for the Department of Energy (DOE). The Defense Waste Processing Facility (DWPF) at SRS is currently vitrifying the waste in borosilicate glass, while the facilities at the Hanford site are in the construction phase. Both processes utilize slurry-fed joule-heated melters to vitrify the waste slurries. The DWPF has experienced difficulty during operations. The cause of the operational problems has been attributed to foaming, gas entrainment and the rheological properties of the process slurries. The rheological properties of the waste slurries limit the total solids content that can be processed by the remote equipment during the pretreatment and meter feed processes. Highly viscous material can lead to air entrainment during agitation and difficulties with pump operations. Excessive foaming in waste evaporators can cause carryover of radionuclides and non-radioactive waste to the condensate system. Experimental and theoretical investigations of the surface phenomena, suspension rheology and bubble generation of interactions that lead to foaming and air entrainment problems in the DOE High Level and Low Activity Radioactive Waste separation and immobilization processes were pursued under this project. The first major task accomplished in the grant proposal involved development of a theoretical model of the phenomenon of foaming in a three-phase gas-liquid-solid slurry system. This work was presented in a recently completed Ph.D. thesis (9). The second major task involved the investigation of the inter-particle interaction and microstructure formation in a model slurry by the batch sedimentation method. Both experiments and modeling studies were carried out. The results were presented in a recently completed Ph.D. thesis. The third task involved the use of laser confocal microscopy to study

  19. Fuel gas conditioning process

    DOEpatents

    Lokhandwala, Kaaeid A.

    2000-01-01

    A process for conditioning natural gas containing C.sub.3+ hydrocarbons and/or acid gas, so that it can be used as combustion fuel to run gas-powered equipment, including compressors, in the gas field or the gas processing plant. Compared with prior art processes, the invention creates lesser quantities of low-pressure gas per unit volume of fuel gas produced. Optionally, the process can also produce an NGL product.

  20. Observing Entrainment Processes Using a Small Unmanned Aerial Vehicle: A Feasibility Study

    NASA Astrophysics Data System (ADS)

    Martin, Sabrina; Beyrich, Frank; Bange, Jens

    2014-03-01

    Measurement flights with the meteorological mini aerial vehicle (MAV) were performed in spring 2011 to assess the capability of an unmanned aerial vehicle (UAV) to measure the structure of the transition zone between the convective boundary layer and the stably stratified free atmosphere. The campaign took place at the Meteorological Observatory Lindenberg/Richard-Aßmann-Observatory of the German Meteorological Service. Besides the MAV flights, observations were made from a 12-m and a 99-m tower, a sodar, two ceilometers, radiosondes, and a tethered balloon with sensor packages at six different levels. MAV measurements were intentionally combined with remote sensing systems. The height range of the entrainment zone as well as its diurnal cycle were provided by the remote sensing instruments. The UAV provided the high-resolution in situ data of temperature and wind for the study of turbulent processes. It is shown that the MAV is able to maintain constant altitude with very small deviations—a pre-requisite to study processes inside the often quite thin entrainment zone and that MAV high-resolution wind and temperature measurements allow for very detailed studies of the fine structure of the atmosphere and thus for the identification of quite local and/or short-duration processes such as overshooting thermals or downward intrusions of warm air. Spatial series measured by the MAV during horizontal flights show turbulent exchange of heat in short turbulent bursts at heights close to and within the entrainment zone. Scaled vertical profiles of vertical velocity, potential temperature variance, and sensible heat flux confirm the general shape found by previous measurements and numerical studies.

  1. Powder synthesis and characterization of nanocrystalline CeO{sub 2} via the combustion processes

    SciTech Connect

    Gu Lina . E-mail: gln@mail.ustc.edu.cn; Meng Guangyao

    2007-07-03

    Nanocrystalline CeO{sub 2} powders were synthesized by the combustion reactions using citric acid and glycol as fuels and nitrate as an oxidant. The adiabatic flame temperatures in the auto ignition processes of the precursors were calculated theoretically. XRD measurements indicated that the powders produced in the combustion processes were cubic fluorite CeO{sub 2} phase. The size and morphology of the particles and extent of agglomeration in the powders were studied using transmission electron microscopy (TEM) and the particle size analyzer respectively. Blue shifts of the absorption peak of the as-prepared powders were observed.

  2. Processing of transparent polycrystalline AlON:Ce3+ scintillators

    DOE PAGESBeta

    Chen, Ching -Fong; Yang, Pin; King, Graham; Tegtmeier, Eric L.

    2015-10-23

    A new polycrystalline ceramic scintillator is reported for potential use in radiation detection and medical imaging applications. The goal was to develop cerium-activated aluminum oxynitride (AlON:Ce3+) ceramics, which can be produced using ceramic processes in comparison to the high-cost, low-yield single-crystal growth technique. A phase pure AlON:Ce3+ powder with cubic symmetry was successfully synthesized at high temperature under a reducing atmosphere to convert Ce4+ to Ce3+ in the solid solution. We explored two different activator concentrations (0.5 and 1.0 mol%). Fully dense and transparent AlON:Ce3+ ceramics were produced by a liquid-phase-assisted pressureless sintering. The crystal field splitting around the Ce3+more » activator in the AlON was comparable to the splitting induced by Br₋ and the Cl₋ ligands, which produced an emission spectrum perfectly matching the maximum quantum efficiency range of the photomultiplier tube for radiation detection. Both optical excitation and radiation ionizations in AlON:Ce3+ were demonstrated. Lastly, challenges and mechanisms related to the radioluminescence efficiency are discussed.« less

  3. Applicability of CeO 2 as a surrogate for PuO 2 in a MOX fuel development

    NASA Astrophysics Data System (ADS)

    Kim, Han Soo; Joung, Chang Yong; Lee, Byung Ho; Oh, Jae Yong; Koo, Yang Hyun; Heimgartner, Peter

    2008-08-01

    The applicability of cerium oxide, as a surrogate for plutonium oxide, was evaluated for the fabrication process of a MOX (mixed oxide) fuel pellet. Sintering behavior, pore former effect and thermal properties of the Ce-MOX were compared with those of Pu-MOX. Compacting parameters of the Pu-MOX powder were optimized by a simulation using Ce-MOX powder. Sintering behavior of Ce-MOX was very similar to that of Pu-MOX, in particular for the oxidative sintering process. The sintered density of both pellets was decreased with the same slope with an increasing DA (dicarbon amide) content. Both the Ce-MOX and Pu-MOX pellets which were fabricated by an admixing of 0.05 wt% DA and sintering in a CO 2 atmosphere had the same average grain size of 11 μm and a density of 95%T.D. The thermal conductivity of the Pu-MOX was a little higher than that of the Ce-MOX at a lower temperature but both conductivities became closer to each other above 900 K. Cerium oxide was found to be a useful surrogate to simulate the Pu behavior in the MOX fuel fabrication.

  4. Solution combustion synthesis of CeO{sub 2}-CeAlO{sub 3} nano-composites by mixture-of-fuels approach

    SciTech Connect

    Aruna, S.T.; Kini, N.S. Rajam, K.S.

    2009-04-02

    Nano-composites of CeO{sub 2}-CeAlO{sub 3} are synthesised by solution combustion method employing (a) urea and (b) a mixture of urea and glycine as fuels with corresponding metal nitrates. The as-prepared powders are all nano-sized (5-30 nm) and the same is confirmed by broadening of the X-ray diffraction peaks and transmission electron microscopy. A starting composition of Ce:Al in the atomic ratio 4:6 gives rise to different phases depending on the fuel being used for combustion. When urea alone is used as fuel, nano-crystalline CeO{sub 2} phase is formed with Al{sub 2}O{sub 3} being in the amorphous state. When the mixture of fuels is used, a mixture of nano-sized CeO{sub 2} and CeAlO{sub 3} phases is obtained. However, upon sintering at 1400 deg. C in air, the stable phases CeO{sub 2} and {alpha}-Al{sub 2}O{sub 3} are formed in both the cases. Combustion synthesis using mixture-of-fuels is proposed to be a route to stabilise low oxidation compounds such as CeAlO{sub 3}.

  5. Small scale processes and entrainment in a stratocumulus marine boundary layer

    SciTech Connect

    Stevens, D.E.; Almgren, A.S.; Bell, J.B.; Beckner, V.E.; Rendleman, C.A.

    1998-05-01

    Lack of resolution is a common problem hampering the use of large eddy simulation models for investigating boundary layer dynamics. Entrainment into the tops of marine stratus is characteristic of this problem. The use of parallel computing as a technique for resolving both boundary layer motions and the entrainment region enables the investigation of the interaction between the moist thermodynamics and turbulence in the entrainment region at very small length scales (dx = 8 m, dz = 4 m). This interaction results in heterogeneity at small scales which is important for correctly diagnosing the details of entrainment. This study presents several numerical experiments at high resolution using a generalization of a 1995 GCSS (GEWEX Cloud System Studies) model intercomparison. Subtle details of the numerical algorithm are found to cause larger differences in entrainment than choice of subgrid model. A kinetic energy budget shows that even for very high resolution, numerical dissipation is usually larger than that produced by the subgrid model. However, the structure of eddies at the inversion is determined mainly by resolution with very little dependence on numerical representation. Inversion properties are converging as resolution approaches an undulation scale. Most of the mixing is confined within 100 meters of the inversion with entraining motions having an aspect ratio of 6 to 1.

  6. Integrated coke, asphalt and jet fuel production process and apparatus

    DOEpatents

    Shang, Jer Y.

    1991-01-01

    A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.

  7. Non-homogeneous hybrid rocket fuel for enhanced regression rates utilizing partial entrainment

    NASA Astrophysics Data System (ADS)

    Boronowsky, Kenny

    A concept was developed and tested to enhance the performance and regression rate of hydroxyl terminated polybutadiene (HTPB), a commonly used hybrid rocket fuel. By adding small nodules of paraffin into the HTPB fuel, a non-homogeneous mixture was created resulting in increased regression rates. The goal was to develop a fuel with a simplified single core geometry and a tailorable regression rate. The new fuel would benefit from the structural stability of HTPB yet not suffer from the large void fraction representative of typical HTPB core geometries. Regression rates were compared between traditional HTPB single core grains, 85% HTPB mixed with 15% (by weight) paraffin cores, 70% HTPB mixed with 30% paraffin cores, and plain paraffin single core grains. Each fuel combination was tested at oxidizer flow rates, ranging from 0.9 - 3.3 g/s of gaseous oxygen, in a small scale hybrid test rocket and average regression rates were measured. While large uncertainties were present in the experimental setup, the overall data showed that the regression rate was enhanced as paraffin concentration increased. While further testing would be required at larger scales of interest, the trends are encouraging. Inclusion of paraffin nodules in the HTPB grain may produce a greater advantage than other more noxious additives in current use. In addition, it may lead to safer rocket motors with higher integrated thrust due to the decreased void fraction.

  8. Measurements and modeling of pulverized fuel char in an entrained flow reactor

    NASA Astrophysics Data System (ADS)

    Kebria, Mazdak

    In recent years, the combustion zone of utility boilers were modified for NOx control and this made the task of maintaining low residual carbon levels in boiler fly ash much more difficult. To predict the relationships between boiler operating conditions and residual carbon-in-ash, there is a need for improvements in determining the appropriate char reactivity to use in simulating coal-fired combustors and in relating this reactivity to unburned coal characteristics. To aid in this effort, a tubular, downward-fired, refractory-lined, laminar entrained flow reactor (EFR) was built to provide a pilot scale environment with 2 seconds residence time for studying coal combustion. Using a commercial CFD code (FLUENT), a three dimensional numerical model of coal burning in the EFR was created to evaluate common char burnout kinetic modeling approaches. EFR experimental data was obtained for operating conditions adjusted to reproduce particle Lagrangian temperature and oxygen concentration time histories typically found in coal-fired utility boilers. The radial temperature profiles were measured at different axial locations in the EFR with a suction pyrometer and thermocouples. The temperature distribution in the reactor agreed well with the simulations. A gas analyzer with a quenching probe was used to measure the oxygen distribution to similarly confirm oxygen distribution in the EFR. A semi-isokinetic particulate sampling probe was used to extract ash samples at different heights in the reactor to measure the evolution of loss on ignition (LOI). Measured LOI values were used to validate the model against predicted values. Reaction kinetics rates in the model were adjusted to bring agreement between calculated LOI and the measured values from the experimental results. The LOI predictions by kinetic-diffusion and CBK model are very similar at the late stage of char burnout. The results indicate that we can achieve sufficient accuracy for the prediction of final carbon

  9. Health Effects Associated with Inhalation Exposure to Diesel Emission Generated with and without CeO2 Nano Fuel Additive

    EPA Science Inventory

    Diesel exhaust (DE) exposure induces adverse cardiopulmonary effects. Addition of nano cerium (Ce) oxide additive to diesel fuel (DECe) increases fuel burning efficiency resulting in altered emission characteristics and potentially altered health effects. We hypothesized that inh...

  10. Inducing attention not to blink: auditory entrainment improves conscious visual processing.

    PubMed

    Ronconi, Luca; Pincham, Hannah L; Szűcs, Dénes; Facoetti, Andrea

    2016-09-01

    Our ability to allocate attention at different moments in time can sometimes fail to select stimuli occurring in close succession, preventing visual information from reaching awareness. This so-called attentional blink (AB) occurs when the second of two targets (T2) is presented closely after the first (T1) in a rapid serial visual presentation (RSVP). We hypothesized that entrainment to a rhythmic stream of stimuli-before visual targets appear-would reduce the AB. Experiment 1 tested the effect of auditory entrainment by presenting sounds with a regular or irregular interstimulus interval prior to a RSVP where T1 and T2 were separated by three possible lags (1, 3 and 8). Experiment 2 examined visual entrainment by presenting visual stimuli in place of auditory stimuli. Results revealed that irrespective of sensory modality, arrhythmic stimuli preceding the RSVP triggered an alerting effect that improved the T2 identification at lag 1, but impaired the recovery from the AB at lag 8. Importantly, only auditory rhythmic entrainment was effective in reducing the AB at lag 3. Our findings demonstrate that manipulating the pre-stimulus condition can reduce deficits in temporal attention characterizing the human cognitive architecture, suggesting innovative trainings for acquired and neurodevelopmental disorders. PMID:26215434

  11. Spent graphite fuel element processing

    SciTech Connect

    Holder, N.D.; Olsen, C.W.

    1981-07-01

    The Department of Energy currently sponsors two programs to demonstrate the processing of spent graphite fuel elements. General Atomic in San Diego operates a cold pilot plant to demonstrate the processing of both US and German high-temperature reactor fuel. Exxon Nuclear Idaho Company is demonstrating the processing of spent graphite fuel elements from Rover reactors operated for the Nuclear Rocket Propulsion Program. This work is done at Idaho National Engineering Laboratory, where a hot facility is being constructed to complete processing of the Rover fuel. This paper focuses on the graphite combustion process common to both programs.

  12. Fuel processing device

    DOEpatents

    Ahluwalia, Rajesh K.; Ahmed, Shabbir; Lee, Sheldon H. D.

    2011-08-02

    An improved fuel processor for fuel cells is provided whereby the startup time of the processor is less than sixty seconds and can be as low as 30 seconds, if not less. A rapid startup time is achieved by either igniting or allowing a small mixture of air and fuel to react over and warm up the catalyst of an autothermal reformer (ATR). The ATR then produces combustible gases to be subsequently oxidized on and simultaneously warm up water-gas shift zone catalysts. After normal operating temperature has been achieved, the proportion of air included with the fuel is greatly diminished.

  13. Small-scale processes and entrainment in a stratocumulus marine boundary layer

    SciTech Connect

    Stevens, D.E.; Bell, J.B.; Almgren, A.S.; Beckner, V.E.; Rendleman, C.A.

    2000-02-15

    Numerical studies of boundary layer meteorology are increasingly reliant on large eddy simulation (LES) models, but few detailed validation studies of these types of models have been done. In this paper, the authors investigate the behavior of an LES model for simulation of a marine boundary layer. Specifically, the authors focus on the mechanisms that control numerical predictions of entrainment into the tops of marine stratus in a moist generalization of the 1995 Global Energy and Water Cycle Experiment Cloud System Studies model intercomparison. For the computational study the authors present a sequence of simulations of varying resolution, from a typical resolution (50 m horizontal and 25 m vertical mesh size) to a fine resolution (8 m horizontal and 4 m vertical mesh size). The authors also explore variations in the model such as different subgrid models and modifications of the advection scheme. It was found that the thickness of the inversion, the depth of entraining eddies, and the shape of vertical velocity spectra were determined mainly by the mesh spacing used. However, the entrainment rate was found to have a distinct dependence on the amount of combined numerical and subgrid-scale mixing. This indicates that the use of large eddy simulation to study mixing in stratocumulus boundary layers needs to account for both sources of mixing.

  14. Monolithic Fuel Fabrication Process Development

    SciTech Connect

    C. R. Clark; N. P. Hallinan; J. F. Jue; D. D. Keiser; J. M. Wight

    2006-05-01

    The pursuit of a high uranium density research reactor fuel plate has led to monolithic fuel, which possesses the greatest possible uranium density in the fuel region. Process developments in fabrication development include friction stir welding tool geometry and cooling improvements and a reduction in the length of time required to complete the transient liquid phase bonding process. Annealing effects on the microstructures of the U-10Mo foil and friction stir welded aluminum 6061 cladding are also examined.

  15. Development of a Ni-Ce0.8Zr0.2O2 catalyst for solid oxide fuel cells operating on ethanol through internal reforming

    NASA Astrophysics Data System (ADS)

    Liao, Mingming; Wang, Wei; Ran, Ran; Shao, Zongping

    2011-08-01

    Inexpensive 20 wt.% Ni-Ce0.8Zr0.2O2 catalysts are synthesized by a glycine nitrate process (GNP) and an impregnation process (IMP). The catalytic activity for ethanol steam reforming (ESR) at 400-650 °C, catalytic stability and carbon deposition properties are investigated. Ni-Ce0.8Zr0.2O2 (GNP) shows a higher catalytic performance than Ni-Ce0.8Zr0.2O2 (IMP), especially at lower temperatures. It also presents a better coking resistance and a lower graphitization degree of the deposited carbon. The superior catalytic activity and coke resistance of Ni-Ce0.8Zr0.2O2 (GNP) is attributed to the small particle size of the active metallic nickel phase and the strong interaction between the nickel and the Ce0.8Zr0.2O2 support, as evidenced by the XRD and H2-TPR. The Ni-Ce0.8Zr0.2O2 (GNP) is further applied as an anode functional layer in solid oxide fuel cells operating on ethanol steam. The cell yields a peak power density of 536 mW cm-2 at 700 °C when operating on EtOH-H2O gas mixtures, which is only slightly lower than that of hydrogen fuel, whereas the cell without the functional layer failed for short-term operations. Ni-Ce0.8Zr0.2O2 (GNP) is promising as an active and highly coking-resistant catalyst layer for solid-oxide fuel cells operating on ethanol steam fuel.

  16. Oil production by entrained pyrolysis of biomass and processing of oil and char

    DOEpatents

    Knight, James A.; Gorton, Charles W.

    1990-01-02

    Entrained pyrolysis of lignocellulosic material proceeds from a controlled pyrolysis-initiating temperature to completion of an oxygen free environment at atmospheric pressure and controlled residence time to provide a high yield recovery of pyrolysis oil together with char and non-condensable, combustible gases. The residence time is a function of gas flow rate and the initiating temperature is likewise a function of the gas flow rate, varying therewith. A controlled initiating temperature range of about 400.degree. C. to 550.degree. C. with corresponding gas flow rates to maximize oil yield is disclosed.

  17. Shaping process makes fuels

    SciTech Connect

    Tabak, S.A.; Krambeck, F.J.

    1985-09-01

    The Mobil Olefin to Gasoline and Distillate (MOGD) process is described in which light olefinic compunds can be converted to high quality gasoline and distillate. This process, now ready for commercialization is based on a unique synthetic zeolite catalyst, the shape of which selectively oligomerizes light olefins to higher molecular weight iso-olefins. The highly flexible process can be designed to produce distillate/gasoline ratios of 0/100 to 90/10 for a commercial plant, depending on market requirements. MOGD is applicable to a wide range of feed streams ranging from ethylene to 400 degrees F end point olefinic naphtha. The process has been tested using commercially produced catalyst in refinery-scale equipment.

  18. Clouds and entrainment. [cumulus convective turbulence in clear air

    NASA Technical Reports Server (NTRS)

    Randall, D. A.

    1982-01-01

    The concept of entrainment is discussed, and the knowledge that has been acquired about entraining turbulence in clear air is surveyed. Attention is then given to observations and models of stratocumulus entrainment, which show some of the ways in which cloudiness modifies the entrainment process. Entraining cumuli are also considered, with some of the differences between cumulus entrainment and stratocumulus entrainment noted. Emphasis is placed on the dynamical aspects of entrainment; its effects on droplet spectra and other microphysical aspects are mentioned only briefly.

  19. Role of Microstructure and Surface Defects on the Dissolution Kinetics of CeO2, a UO2 Fuel Analogue.

    PubMed

    Corkhill, Claire L; Bailey, Daniel J; Tocino, Florent Y; Stennett, Martin C; Miller, James A; Provis, John L; Travis, Karl P; Hyatt, Neil C

    2016-04-27

    The release of radionuclides from spent fuel in a geological disposal facility is controlled by the surface mediated dissolution of UO2 in groundwater. In this study we investigate the influence of reactive surface sites on the dissolution of a synthesized CeO2 analogue for UO2 fuel. Dissolution was performed on the following: CeO2 annealed at high temperature, which eliminated intrinsic surface defects (point defects and dislocations); CeO2-x annealed in inert and reducing atmospheres to induce oxygen vacancy defects and on crushed CeO2 particles of different size fractions. BET surface area measurements were used as an indicator of reactive surface site concentration. Cerium stoichiometry, determined using X-ray Photoelectron Spectroscopy (XPS) and supported by X-ray Diffraction (XRD) analysis, was used to determine oxygen vacancy concentration. Upon dissolution in nitric acid medium at 90 °C, a quantifiable relationship was established between the concentration of high energy surface sites and CeO2 dissolution rate; the greater the proportion of intrinsic defects and oxygen vacancies, the higher the dissolution rate. Dissolution of oxygen vacancy-containing CeO2-x gave rise to rates that were an order of magnitude greater than for CeO2 with fewer oxygen vacancies. While enhanced solubility of Ce(3+) influenced the dissolution, it was shown that replacement of vacancy sites by oxygen significantly affected the dissolution mechanism due to changes in the lattice volume and strain upon dissolution and concurrent grain boundary decohesion. These results highlight the significant influence of defect sites and grain boundaries on the dissolution kinetics of UO2 fuel analogues and reduce uncertainty in the long term performance of spent fuel in geological disposal. PMID:27022662

  20. Process for removal of sulfur compounds from fuel gases

    DOEpatents

    Moore, Raymond H.; Stegen, Gary E.

    1978-01-01

    Fuel gases such as those produced in the gasification of coal are stripped of sulfur compounds and particulate matter by contact with molten metal salt. The fuel gas and salt are intimately mixed by passage through a venturi or other constriction in which the fuel gas entrains the molten salt as dispersed droplets to a gas-liquid separator. The separated molten salt is divided into a major and a minor flow portion with the minor flow portion passing on to a regenerator in which it is contacted with steam and carbon dioxide as strip gas to remove sulfur compounds. The strip gas is further processed to recover sulfur. The depleted, minor flow portion of salt is passed again into contact with the fuel gas for further sulfur removal from the gas. The sulfur depleted, fuel gas then flows through a solid absorbent for removal of salt droplets. The minor flow portion of the molten salt is then recombined with the major flow portion for feed to the venturi.

  1. Design of Pt-CeOx hetero-interface on electrodes in polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Mori, T.; Fugane, K.; Chauhan, S.; Ito, M.; Masuda, T.; Noguchi, H.; Uosaki, K.

    2014-03-01

    Pt-CeOx interface on Pt electrodes was prepared for improvement of both oxygen reduction reaction (ORR) activity of Pt cathode and CO tolerance of Pt anode. The surface of Pt-CeOx nano-particle/C electrode mainly consists of metallic Pt, ionized Pt (i.e. Pt2+) and Ce3+ species. The ORR activity on Pt was improved by the formation of Pt-CeOx interface. In-situ XAFS analysis suggests that cerium oxide surface in the Pt-CeOx/C was oxidized instead of Pt surface by electrochemical redox reaction of CeOx at room temperature. This suggests that the Pt-CeOx interface plays key role for improvement of cathode performance. Also, CO tolerance of Pt was improved by the formation of aforementioned interface. The improvement of CO tolerance of Pt was also observed by using in-situ IR analysis. Based on all experimental data, it is concluded that the design of defect structure in Pt-CeOx provides us opportunity to make the breakthrough electrodes for fuel cell application.

  2. Processing sunflower oil for fuel

    SciTech Connect

    Backer, L.F.; Jacobsen, L.; Olson, C.

    1982-05-01

    Research on processing of sunflower seed for oil was initiated to evaluate the equipment that might adapt best to on-farm or small factory production facilities. The first devices identified for evaluation were auger press expeller units, primary oil cleaning equipment, and final filters. A series of standard finishing filtration tests were carried out on sunflower oil and sunflower oil - diesel fuel blends using sunflower oil from four different sources.

  3. Synthetic fuels handbook: properties, process and performance

    SciTech Connect

    Speight, J.

    2008-07-01

    The handbook is a comprehensive guide to the benefits and trade-offs of numerous alternative fuels, presenting expert analyses of the different properties, processes, and performance characteristics of each fuel. It discusses the concept systems and technology involved in the production of fuels on both industrial and individual scales. Chapters 5 and 7 are of special interest to the coal industry. Contents: Chapter 1. Fuel Sources - Conventional and Non-conventional; Chapter 2. Natural Gas; Chapter 3. Fuels From Petroleum and Heavy Oil; Chapter 4. Fuels From Tar Sand Bitumen; Chapter 5. Fuels From Coal; Chapter 6. Fuels From Oil Shale; Chapter 7. Fuels From Synthesis Gas; Chapter 8. Fuels From Biomass; Chapter 9. Fuels From Crops; Chapter 10. Fuels From Wood; Chapter 11. Fuels From Domestic and Industrial Waste; Chapter 12. Landfill Gas. 3 apps.

  4. Microbial fuel cell treatment of fuel process wastewater

    DOEpatents

    Borole, Abhijeet P; Tsouris, Constantino

    2013-12-03

    The present invention is directed to a method for cleansing fuel processing effluent containing carbonaceous compounds and inorganic salts, the method comprising contacting the fuel processing effluent with an anode of a microbial fuel ell, the anode containing microbes thereon which oxidatively degrade one or more of the carbonaceous compounds while producing electrical energy from the oxidative degradation, and directing the produced electrical energy to drive an electrosorption mechanism that operates to reduce the concentration of one or more inorganic salts in the fuel processing effluent, wherein the anode is in electrical communication with a cathode of the microbial fuel cell. The invention is also directed to an apparatus for practicing the method.

  5. Characterization and ecological risk assessment of nanoparticulate CeO2 as a diesel fuel catalyst.

    PubMed

    Batley, Graeme E; Halliburton, Brendan; Kirby, Jason K; Doolette, Casey L; Navarro, Divina; McLaughlin, Mike J; Veitch, Colin

    2013-08-01

    Nanoparticulate cerium dioxide (nano-CeO2 ), when combusted as an additive to diesel fuel, was transformed from 6 nm to 14 nm sizes into particles near 43 nm, with no obvious change in the unit cell dimensions or crystalline form. Cerium sulfate, if formed during combustion, was below detection limits. Ceria nanoparticles were agglomerated within the soot matrix, with a mean aerodynamic diameter near 100 nm. The dissolution of cerium from the dried ceria catalyst in synthetic soft water was extremely small (<0.0006% or <0.2 µg Ce/L), with particles being highly agglomerated (<450 nm). Agglomeration was reduced in the presence of humic acid. In the combusted samples, soot was dominant, and the solubility of cerium in soft water showed an almost 100-fold increase in the <1 nm fraction compared to that before combustion. It appeared that the nano-CeO2 remained agglomerated within the soot matrix and would not be present as dispersed nanoparticles in aquatic or soil environments. Despite the increased dissolution, the solubility was not sufficient for the combusted ceria to represent a risk in aquatic ecosystems. The predicted environmental concentrations were still orders of magnitude below the predicted no effects concentration of near 1 mg/L. In the soil environment, any cerium released from soot materials would interact with natural colloids, decreasing cerium concentrations in soil solutions and further minimizing the potential risk to soil organisms. PMID:23595783

  6. Separation and detection of amino acid metabolites of Escherichia coli in microbial fuel cell with CE.

    PubMed

    Wang, Wei; Ma, Lihong; Lin, Ping; Xu, Kaixuan

    2016-07-01

    In this work, CE-LIF was employed to investigate the amino acid metabolites produced by Escherichia coli (E. coli) in microbial fuel cell (MFC). Two peptides, l-carnosine and l-alanyl-glycine, together with six amino acids, cystine, alanine, lysine, methionine, tyrosine, arginine were separated and detected in advance by a CE-LIF system coupled with a homemade spontaneous injection device. The injection device was devised to alleviate the effect of electrical discrimination for analytes during sample injection. All analytes could be completely separated within 8 min with detection limits of 20-300 nmol/L. Then this method was applied to analyze the substrate solution containing amino acid metabolites produced by E. coli. l-carnosine, l-alanyl-glycine, and cystine were used as the carbon, nitrogen, and sulfur source for the E. coli culture in the MFC to investigate the amino acid metabolites during metabolism. Two MFCs were used to compare the activity of metabolism of the bacteria. In the sample collected at the running time 200 h of MFC, the amino acid methionine was discovered as the metabolite with the concentrations 23.3 μg/L. PMID:27121957

  7. Tracking cortical entrainment in neural activity: auditory processes in human temporal cortex

    PubMed Central

    Thwaites, Andrew; Nimmo-Smith, Ian; Fonteneau, Elisabeth; Patterson, Roy D.; Buttery, Paula; Marslen-Wilson, William D.

    2015-01-01

    A primary objective for cognitive neuroscience is to identify how features of the sensory environment are encoded in neural activity. Current auditory models of loudness perception can be used to make detailed predictions about the neural activity of the cortex as an individual listens to speech. We used two such models (loudness-sones and loudness-phons), varying in their psychophysiological realism, to predict the instantaneous loudness contours produced by 480 isolated words. These two sets of 480 contours were used to search for electrophysiological evidence of loudness processing in whole-brain recordings of electro- and magneto-encephalographic (EMEG) activity, recorded while subjects listened to the words. The technique identified a bilateral sequence of loudness processes, predicted by the more realistic loudness-sones model, that begin in auditory cortex at ~80 ms and subsequently reappear, tracking progressively down the superior temporal sulcus (STS) at lags from 230 to 330 ms. The technique was then extended to search for regions sensitive to the fundamental frequency (F0) of the voiced parts of the speech. It identified a bilateral F0 process in auditory cortex at a lag of ~90 ms, which was not followed by activity in STS. The results suggest that loudness information is being used to guide the analysis of the speech stream as it proceeds beyond auditory cortex down STS toward the temporal pole. PMID:25713530

  8. Low-Frequency Cortical Entrainment to Speech Reflects Phoneme-Level Processing.

    PubMed

    Di Liberto, Giovanni M; O'Sullivan, James A; Lalor, Edmund C

    2015-10-01

    The human ability to understand speech is underpinned by a hierarchical auditory system whose successive stages process increasingly complex attributes of the acoustic input. It has been suggested that to produce categorical speech perception, this system must elicit consistent neural responses to speech tokens (e.g., phonemes) despite variations in their acoustics. Here, using electroencephalography (EEG), we provide evidence for this categorical phoneme-level speech processing by showing that the relationship between continuous speech and neural activity is best described when that speech is represented using both low-level spectrotemporal information and categorical labeling of phonetic features. Furthermore, the mapping between phonemes and EEG becomes more discriminative for phonetic features at longer latencies, in line with what one might expect from a hierarchical system. Importantly, these effects are not seen for time-reversed speech. These findings may form the basis for future research on natural language processing in specific cohorts of interest and for broader insights into how brains transform acoustic input into meaning. PMID:26412129

  9. Nanostructured Gd-CeO2 electrolyte for solid oxide fuel cell by aqueous tape casting

    NASA Astrophysics Data System (ADS)

    Akbari-Fakhrabadi, A.; Mangalaraja, R. V.; Sanhueza, Felipe A.; Avila, Ricardo E.; Ananthakumar, S.; Chan, S. H.

    2012-11-01

    Gadolinia-doped ceria (Ce0.9Gd0.1O1.95, GDC) electrolyte was fabricated by aqueous-based tape casting method for solid oxide fuel cells (SOFCs). The ceramic powder prepared by combustion synthesis was used with poly acrylic acid (PAA), poly vinyl alcohol (PVA), poly ethylene glycol (PEG), Octanol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate and double distilled water as dispersant, binder, plasticizer, defoamer, surfactant and solvent respectively, to prepare stable GDC slurry. The conditions for preparing stable GDC slurries were studied and optimized by sedimentation, zeta potential and viscosity measurements. Green tapes with smooth surface, flexibility, thickness in the range of 0.35-0.4 mm and 45% relative green density were prepared. Conventional and flash sintering techniques were used and compared for densification which demonstrated the possibility of surpassing sintering at high temperatures and retarding related grain growth.

  10. Fast Reactor Spent Fuel Processing: Experience and Criticality Safety

    SciTech Connect

    Chad Pope

    2007-05-01

    This paper discusses operational and criticality safety experience associated with the Idaho National Laboratory Fuel Conditioning Facility which uses a pyrometallurgical process to treat spent fast reactor metallic fuel. The process is conducted in an inert atmosphere hot cell. The process starts with chopping metallic fuel elements into a basket. The basket is lowered into molten salt (LiCl-KCl) along with a steel mandrel. Active metal fission products, transuranic metals and sodium metal in the spent fuel undergo chemical oxidation and form chlorides. Voltage is applied between the basket, which serves as an anode, and the mandrel, which serves as a cathode, causing metallic uranium in the spent fuel to undergo electro-chemical oxidation thereby forming uranium chloride. Simultaneously at the cathode, uranium chloride undergoes electro-chemical reduction and deposits uranium metal onto the mandrel. The uranium metal and accompanying entrained salt are placed in a distillation furnace where the uranium melts forming an ingot and the entrained salt boils and subsequently condenses in a separate crucible. The uranium ingots are placed in long term storage. During the ten year operating history, over one hundred criticality safety evaluations were prepared. All criticality safety related limits and controls for the entire process are contained in a single document which required over thirty revisions to accommodate the process changes. Operational implementation of the limits and controls includes use of a near real-time computerized tracking system. The tracking system uses an Oracle database coupled with numerous software applications. The computerized tracking system includes direct fuel handler interaction with every movement of material. Improvements to this system during the ten year history include introduction of web based operator interaction, tracking of moderator materials and the development of a plethora database queries to assist in day to day

  11. Dry process dependency of dupic fuel cycle

    SciTech Connect

    Park, Kwangheon; Whang, Juho; Kim, Yun-goo; Kim, Heemoon

    1996-12-31

    During the Dry Process, volatile and semi-volatile elements are released from the fuel. The effects of these released radioactive nuclides on DUPIC fuel cycle are analyzed from the view-point of radiation hazard, decay beat, and hazard index. Radiation hazard of fresh and spent DUPIC fuel is sensitive to the method of Dry Process. Decay beat of the fuel is also affected. Hazard index turned out not to be dependent on Dry Process.

  12. Processing of transparent polycrystalline AlON:Ce3+ scintillators

    SciTech Connect

    Chen, Ching -Fong; Yang, Pin; King, Graham; Tegtmeier, Eric L.

    2015-10-23

    A new polycrystalline ceramic scintillator is reported for potential use in radiation detection and medical imaging applications. The goal was to develop cerium-activated aluminum oxynitride (AlON:Ce3+) ceramics, which can be produced using ceramic processes in comparison to the high-cost, low-yield single-crystal growth technique. A phase pure AlON:Ce3+ powder with cubic symmetry was successfully synthesized at high temperature under a reducing atmosphere to convert Ce4+ to Ce3+ in the solid solution. We explored two different activator concentrations (0.5 and 1.0 mol%). Fully dense and transparent AlON:Ce3+ ceramics were produced by a liquid-phase-assisted pressureless sintering. The crystal field splitting around the Ce3+ activator in the AlON was comparable to the splitting induced by Br₋ and the Cl₋ ligands, which produced an emission spectrum perfectly matching the maximum quantum efficiency range of the photomultiplier tube for radiation detection. Both optical excitation and radiation ionizations in AlON:Ce3+ were demonstrated. Lastly, challenges and mechanisms related to the radioluminescence efficiency are discussed.

  13. Partial entrainment of gravel bars during floods

    USGS Publications Warehouse

    Konrad, C.P.; Booth, D.B.; Burges, S.J.; Montgomery, D.R.

    2002-01-01

    Spatial patterns of bed material entrainment by floods were documented at seven gravel bars using arrays of metal washers (bed tags) placed in the streambed. The observed patterns were used to test a general stochastic model that bed material entrainment is a spatially independent, random process where the probability of entrainment is uniform over a gravel bar and a function of the peak dimensionless shear stress ??*0 of the flood. The fraction of tags missing from a gravel bar during a flood, or partial entrainment, had an approximately normal distribution with respect to ??*0 with a mean value (50% of the tags entrained) of 0.085 and standard deviation of 0.022 (root-mean-square error of 0.09). Variation in partial entrainment for a given ??*0 demonstrated the effects of flow conditioning on bed strength, with lower values of partial entrainment after intermediate magnitude floods (0.065 < ??*0 < 0.08) than after higher magnitude floods. Although the probability of bed material entrainment was approximately uniform over a gravel bar during individual floods and independent from flood to flood, regions of preferential stability and instability emerged at some bars over the course of a wet season. Deviations from spatially uniform and independent bed material entrainment were most pronounced for reaches with varied flow and in consecutive floods with small to intermediate magnitudes.

  14. Effect of oxidizer to fuel molar ratio on particle size and DC conductivity of CeO2 nanoparticles

    NASA Astrophysics Data System (ADS)

    Harish, B. M.; Rajeeva, M. P.; Naveen, C. S.; Chaturmukha, V. S.; Avinash, B. S.; Jayanna, H. S.; Lamani, Ashok R.

    2016-05-01

    Cerium oxide nanoparticles were synthesized by solution combustion method with varying the oxidizer (cerium nitrate hexa hydrate) to fuel (Glycine) molar ratio. The prepared samples were characterized by UV-visible spectrometer, X-ray diffractometer (XRD), Scanning electron microscope (SEM) and Energy dispersive X-Ray analysis (EDAX). XRD pattern reveals the formation of cubic fluorite structure of CeO2. It was observed that finest crystallites were found at extreme fuel-deficient condition and it is good enough to produce favorable powder characteristics. The average crystallite size was found to be 14.46 nm to 21.57 nm. The temperature dependent dc conductivity was carried out using Keithley source meter between the temperature range from 300K to 573K. From this study it was found that the conductivity increases with increase of temperature due to semiconducting behavior of CeO2 and it decreases with particle size due to increase in the energy band gap.

  15. Fuel quality processing study, volume 1

    NASA Astrophysics Data System (ADS)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Syverson, H. T.; Klumpe, H. W.; Kessler, R. E.; Kotzot, H. T.; Loran, B. L.

    1981-04-01

    A fuel quality processing study to provide a data base for an intelligent tradeoff between advanced turbine technology and liquid fuel quality, and also, to guide the development of specifications of future synthetic fuels anticipated for use in the time period 1985 to 2000 is given. Four technical performance tests are discussed: on-site pretreating, existing refineries to upgrade fuels, new refineries to upgrade fuels, and data evaluation. The base case refinery is a modern Midwest refinery processing 200,000 BPD of a 60/40 domestic/import petroleum crude mix. The synthetic crudes used for upgrading to marketable products and turbine fuel are shale oil and coal liquids. Of these syncrudes, 50,000 BPD are processed in the existing petroleum refinery, requiring additional process units and reducing petroleum feed, and in a new refinery designed for processing each syncrude to produce gasoline, distillate fuels, resid fuels, and turbine fuel, JPGs and coke. An extensive collection of synfuel properties and upgrading data was prepared for the application of a linear program model to investigate the most economical production slate meeting petroleum product specifications and turbine fuels of various quality grades. Technical and economic projections were developed for 36 scenarios, based on 4 different crude feeds to either modified existing or new refineries operated in 2 different modes to produce 7 differing grades of turbine fuels. A required product selling price of turbine fuel for each processing route was calculated. Procedures and projected economics were developed for on-site treatment of turbine fuel to meet limitations of impurities and emission of pollutants.

  16. Fuel quality processing study, volume 1

    NASA Technical Reports Server (NTRS)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Syverson, H. T.; Klumpe, H. W.; Kessler, R. E.; Kotzot, H. T.; Loran, B. L.

    1981-01-01

    A fuel quality processing study to provide a data base for an intelligent tradeoff between advanced turbine technology and liquid fuel quality, and also, to guide the development of specifications of future synthetic fuels anticipated for use in the time period 1985 to 2000 is given. Four technical performance tests are discussed: on-site pretreating, existing refineries to upgrade fuels, new refineries to upgrade fuels, and data evaluation. The base case refinery is a modern Midwest refinery processing 200,000 BPD of a 60/40 domestic/import petroleum crude mix. The synthetic crudes used for upgrading to marketable products and turbine fuel are shale oil and coal liquids. Of these syncrudes, 50,000 BPD are processed in the existing petroleum refinery, requiring additional process units and reducing petroleum feed, and in a new refinery designed for processing each syncrude to produce gasoline, distillate fuels, resid fuels, and turbine fuel, JPGs and coke. An extensive collection of synfuel properties and upgrading data was prepared for the application of a linear program model to investigate the most economical production slate meeting petroleum product specifications and turbine fuels of various quality grades. Technical and economic projections were developed for 36 scenarios, based on 4 different crude feeds to either modified existing or new refineries operated in 2 different modes to produce 7 differing grades of turbine fuels. A required product selling price of turbine fuel for each processing route was calculated. Procedures and projected economics were developed for on-site treatment of turbine fuel to meet limitations of impurities and emission of pollutants.

  17. Parallel Signal Processing and System Simulation using aCe

    NASA Technical Reports Server (NTRS)

    Dorband, John E.; Aburdene, Maurice F.

    2003-01-01

    Recently, networked and cluster computation have become very popular for both signal processing and system simulation. A new language is ideally suited for parallel signal processing applications and system simulation since it allows the programmer to explicitly express the computations that can be performed concurrently. In addition, the new C based parallel language (ace C) for architecture-adaptive programming allows programmers to implement algorithms and system simulation applications on parallel architectures by providing them with the assurance that future parallel architectures will be able to run their applications with a minimum of modification. In this paper, we will focus on some fundamental features of ace C and present a signal processing application (FFT).

  18. Entrainment Rate in Shallow Cumuli: Dependence on Entrained Dry Air Sources and Probability Density Functions

    NASA Astrophysics Data System (ADS)

    Lu, C.; Liu, Y.; Niu, S.; Vogelmann, A. M.

    2012-12-01

    In situ aircraft cumulus observations from the RACORO field campaign are used to estimate entrainment rate for individual clouds using a recently developed mixing fraction approach. The entrainment rate is computed based on the observed state of the cloud core and the state of the air that is laterally mixed into the cloud at its edge. The computed entrainment rate decreases when the air is entrained from increasing distance from the cloud core edge; this is because the air farther away from cloud edge is drier than the neighboring air that is within the humid shells around cumulus clouds. Probability density functions of entrainment rate are well fitted by lognormal distributions at different heights above cloud base for different dry air sources (i.e., different source distances from the cloud core edge). Such lognormal distribution functions are appropriate for inclusion into future entrainment rate parameterization in large scale models. To the authors' knowledge, this is the first time that probability density functions of entrainment rate have been obtained in shallow cumulus clouds based on in situ observations. The reason for the wide spread of entrainment rate is that the observed clouds are affected by entrainment mixing processes to different extents, which is verified by the relationships between the entrainment rate and cloud microphysics/dynamics. The entrainment rate is negatively correlated with liquid water content and cloud droplet number concentration due to the dilution and evaporation in entrainment mixing processes. The entrainment rate is positively correlated with relative dispersion (i.e., ratio of standard deviation to mean value) of liquid water content and droplet size distributions, consistent with the theoretical expectation that entrainment mixing processes are responsible for microphysics fluctuations and spectral broadening. The entrainment rate is negatively correlated with vertical velocity and dissipation rate because entrainment

  19. A processing centre for the CNES CE-GPS experimentation

    NASA Technical Reports Server (NTRS)

    Suard, Norbert; Durand, Jean-Claude

    1994-01-01

    CNES is involved in a GPS (Global Positioning System) geostationary overlay experimentation. The purpose of this experimentation is to test various new techniques in order to select the optimal station synchronization method, as well as the geostationary spacecraft orbitography method. These new techniques are needed to develop the Ranging GPS Integrity Channel services. The CNES experimentation includes three transmitting/receiving ground stations (manufactured by IN-SNEC), one INMARSAT 2 C/L band transponder and a processing center named STE (Station de Traitements de l'Experimentation). Not all the techniques to be tested are implemented, but the experimental system has to include several functions; part of the future system simulation functions, such as a servo-loop function, and in particular a data collection function providing for rapid monitoring of system operation, analysis of existing ground station processes, and several weeks of data coverage for other scientific studies. This paper discusses system architecture and some criteria used in its design, as well as the monitoring function, the approach used to develop a low-cost and short-life processing center in collaboration with a CNES sub-contractor (ATTDATAID), and some results.

  20. Dry Processing of Used Nuclear Fuel

    SciTech Connect

    K. M. Goff; M. F. Simpson

    2009-09-01

    Dry (non-aqueous) separations technologies have been used for treatment of used nuclear fuel since the 1960s, and they are still being developed and demonstrated in many countries. Dry technologies offer potential advantages compared to traditional aqueous separations including: compactness, resistance to radiation effects, criticality control benefits, compatibility with advanced fuel types, and ability to produce low purity products. Within the Department of Energy’s Advanced Fuel Cycle Initiative, an electrochemical process employing molten salts is being developed for recycle of fast reactor fuel and treatment of light water reactor oxide fuel to produce a feed for fast reactors. Much of the development of this technology is based on treatment of used Experimental Breeder Reactor II (EBR-II) fuel, which is metallic. Electrochemical treatment of the EBR-II fuel has been ongoing in the Fuel Conditioning Facility, located at the Materials and Fuel Complex of Idaho National Laboratory since 1996. More than 3.8 metric tons of heavy metal of metallic fast reactor fuel have been treated using this technology. This paper will summarize the status of electrochemical development and demonstration activities with used nuclear fuel, including high-level waste work. A historic perspective on the background of dry processing will also be provided.

  1. Prediction and measurement of entrained flow coal gasification processes. Interim report, September 8, 1981-September 7, 1983

    SciTech Connect

    Hedman, P.O.; Smoot, L.D.; Fletcher, T.H.; Smith, P.J.; Blackham, A.U.

    1984-01-31

    This volume reports interim experimental and theoretical results of the first two years of a three year study of entrained coal gasification with steam and oxygen. The gasifier facility and testing methods were revised and improved. The gasifier was also modified for high pressure operation. Six successful check-out tests at elevated pressure were performed (55, 75, 100, 130, 170, and 215 psig), and 8 successful mapping tests were performed with the Utah bituminous coal at an elevated pressure of 137.5 psig. Also, mapping tests were performed at atmospheric pressure with a Utah bituminous coal (9 tests) and with a Wyoming subbituminous coal (14 tests). The LDV system was used on the cold-flow facility to make additional nonreactive jets mixing measurements (local mean and turbulent velocity) that could be used to help validate the two-dimensional code. The previously completed two-dimensional entrained coal gasification code, PCGC-2, was evaluated through rigorous comparison with cold-flow, pulverized coal combustion, and entrained coal gasification data. Data from this laboratory were primarily used but data from other laboratories were used when available. A complete set of the data used has been compiled into a Data Book which is included as a supplemental volume of this interim report. A revised user's manual for the two-dimensional code has been prepared and is also included as a part of this interim report. Three technical papers based on the results of this study were published or prepared. 107 references, 57 figures, 35 tables.

  2. Powder handling for automated fuel processing

    SciTech Connect

    Frederickson, J.R.; Eschenbaum, R.C.; Goldmann, L.H.

    1989-04-09

    Installation of the Secure Automated Fabrication (SAF) line has been completed. It is located in the Fuel Cycle Plant (FCP) at the Department of Energy's (DOE) Hanford site near Richland, Washington. The SAF line was designed to fabricate advanced reactor fuel pellets and assemble fuel pins by automated, remote operation. This paper describes powder handling equipment and techniques utilized for automated powder processing and powder conditioning systems in this line. 9 figs.

  3. Mathematical modeling of biomass fuels formation process

    SciTech Connect

    Gaska, Krzysztof Wandrasz, Andrzej J.

    2008-07-01

    The increasing demand for thermal and electric energy in many branches of industry and municipal management accounts for a drastic diminishing of natural resources (fossil fuels). Meanwhile, in numerous technical processes, a huge mass of wastes is produced. A segregated and converted combustible fraction of the wastes, with relatively high calorific value, may be used as a component of formed fuels. The utilization of the formed fuel components from segregated groups of waste in associated processes of co-combustion with conventional fuels causes significant savings resulting from partial replacement of fossil fuels, and reduction of environmental pollution resulting directly from the limitation of waste migration to the environment (soil, atmospheric air, surface and underground water). The realization of technological processes with the utilization of formed fuel in associated thermal systems should be qualified by technical criteria, which means that elementary processes as well as factors of sustainable development, from a global viewpoint, must not be disturbed. The utilization of post-process waste should be preceded by detailed technical, ecological and economic analyses. In order to optimize the mixing process of fuel components, a mathematical model of the forming process was created. The model is defined as a group of data structures which uniquely identify a real process and conversion of this data in algorithms based on a problem of linear programming. The paper also presents the optimization of parameters in the process of forming fuels using a modified simplex algorithm with a polynomial worktime. This model is a datum-point in the numerical modeling of real processes, allowing a precise determination of the optimal elementary composition of formed fuels components, with assumed constraints and decision variables of the task.

  4. Fuel quality/processing study. Volume 3: Fuel upgrading studies

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.; Bruggink, P.; Sinnett, C.

    1981-01-01

    The methods used to calculate the refinery selling prices for the turbine fuels of low quality are described. Detailed descriptions and economics of the upgrading schemes are included. These descriptions include flow diagrams showing the interconnection between processes and the stream flows involved. Each scheme is in a complete, integrated, stand alone facility. Except for the purchase of electricity and water, each scheme provides its own fuel and manufactures, when appropriate, its own hydrogen.

  5. Hydrodynamic Simulations of H Entrainment at the Top of He-shell Flash Convection

    NASA Astrophysics Data System (ADS)

    Woodward, Paul R.; Herwig, Falk; Lin, Pei-Hung

    2015-01-01

    We present the first three-dimensional, fully compressible gas-dynamics simulations in 4π geometry of He-shell flash convection with proton-rich fuel entrainment at the upper boundary. This work is motivated by the insufficiently understood observed consequences of the H-ingestion flash in post-asymptotic giant branch (post-AGB) stars (Sakurai's object) and metal-poor AGB stars. Our investigation is focused on the entrainment process at the top convection boundary and on the subsequent advection of H-rich material into deeper layers, and we therefore ignore the burning of the proton-rich fuel in this study. We find that for our deep convection zone, coherent convective motions of near global scale appear to dominate the flow. At the top boundary convective shear flows are stable against Kelvin-Helmholtz instabilities. However, such shear instabilities are induced by the boundary-layer separation in large-scale, opposing flows. This links the global nature of thick shell convection with the entrainment process. We establish the quantitative dependence of the entrainment rate on grid resolution. With our numerical technique, simulations with 10243 cells or more are required to reach a numerical fidelity appropriate for this problem. However, only the result from the 15363 simulation provides a clear indication that we approach convergence with regard to the entrainment rate. Our results demonstrate that our method, which is described in detail, can provide quantitative results related to entrainment and convective boundary mixing in deep stellar interior environments with very stiff convective boundaries. For the representative case we study in detail, we find an entrainment rate of 4.38 ± 1.48 × 10-13 M ⊙ s-1.

  6. HYDRODYNAMIC SIMULATIONS OF H ENTRAINMENT AT THE TOP OF He-SHELL FLASH CONVECTION

    SciTech Connect

    Woodward, Paul R.; Lin, Pei-Hung; Herwig, Falk E-mail: fherwig@uvic.ca

    2015-01-01

    We present the first three-dimensional, fully compressible gas-dynamics simulations in 4π geometry of He-shell flash convection with proton-rich fuel entrainment at the upper boundary. This work is motivated by the insufficiently understood observed consequences of the H-ingestion flash in post-asymptotic giant branch (post-AGB) stars (Sakurai's object) and metal-poor AGB stars. Our investigation is focused on the entrainment process at the top convection boundary and on the subsequent advection of H-rich material into deeper layers, and we therefore ignore the burning of the proton-rich fuel in this study. We find that for our deep convection zone, coherent convective motions of near global scale appear to dominate the flow. At the top boundary convective shear flows are stable against Kelvin-Helmholtz instabilities. However, such shear instabilities are induced by the boundary-layer separation in large-scale, opposing flows. This links the global nature of thick shell convection with the entrainment process. We establish the quantitative dependence of the entrainment rate on grid resolution. With our numerical technique, simulations with 1024{sup 3} cells or more are required to reach a numerical fidelity appropriate for this problem. However, only the result from the 1536{sup 3} simulation provides a clear indication that we approach convergence with regard to the entrainment rate. Our results demonstrate that our method, which is described in detail, can provide quantitative results related to entrainment and convective boundary mixing in deep stellar interior environments with very stiff convective boundaries. For the representative case we study in detail, we find an entrainment rate of 4.38 ± 1.48 × 10{sup –13} M {sub ☉} s{sup –1}.

  7. Process for vaporizing a liquid hydrocarbon fuel

    DOEpatents

    Szydlowski, Donald F.; Kuzminskas, Vaidotas; Bittner, Joseph E.

    1981-01-01

    The object of the invention is to provide a process for vaporizing liquid hydrocarbon fuels efficiently and without the formation of carbon residue on the apparatus used. The process includes simultaneously passing the liquid fuel and an inert hot gas downwardly through a plurality of vertically spaed apart regions of high surface area packing material. The liquid thinly coats the packing surface, and the sensible heat of the hot gas vaporizes this coating of liquid. Unvaporized liquid passing through one region of packing is uniformly redistributed over the top surface of the next region until all fuel has been vaporized using only the sensible heat of the hot gas stream.

  8. Prediction and measurement of optimum operating conditions for entrained coal gasification processes. Quarterly technical progress report, No. 1, 1 November 1979-31 January 1980

    SciTech Connect

    Smoot, L.D.; Hedman, P.O.; Smith, P.J.

    1980-02-15

    This report summarizes work completed to predict and measure optimum operating conditions for entrained coal gasifications processes. This study is the third in a series designed to investigate mixing and reaction in entrained coal gasifiers. A new team of graduate and undergraduate students was formed to conduct the experiments on optimum gasification operating conditions. Additional coal types, which will be tested in the gasifier were identified, ordered, and delivered. Characterization of these coals will be initiated. Hardware design modifications to introduce swirl into the secondary were initiated. Minor modifications were made to the gasifier to allow laser diagnostics to be made on an independently funded study with the Los Alamos Scientific Laboratory. The tasks completed on the two-dimensional model included the substantiation of a Gaussian PDF for the top-hat PDF in BURN and the completion of a Lagrangian particle turbulent dispersion module. The reacting submodel is progressing into the final stages of debug. The formulation of the radiation submodel is nearly complete and coding has been initiated. A device was designed, fabricated, and used to calibrate the actual Swirl Number of the cold-flow swirl generator used in the Phase 2 study. Swirl calibrations were obtained at the normal tests flow rates and at reduced flow rates. Two cold-flow tests were also performed to gather local velocity data under swirling conditions. Further analysis of the cold-flow coal-dust and swirl test results from the previous Phase 2 study were completed.

  9. CeO2 nanocubes-graphene oxide as durable and highly active catalyst support for proton exchange membrane fuel cell

    PubMed Central

    Lei, M.; Wang, Z. B.; Li, J. S.; Tang, H. L.; Liu, W. J.; Wang, Y. G.

    2014-01-01

    Rapid degradation of cell performance still remains a significant challenge for proton exchange membrane fuel cell (PEMFC). In this work, we develop novel CeO2 nanocubes-graphene oxide nanocomposites as durable and highly active catalyst support for proton exchange membrane fuel cell. We show that the use of CeO2 as the radical scavenger in the catalysts remarkably improves the durability of the catalyst. The catalytic activity retention of Pt-graphene oxide-8 wt.% CeO2 nanocomposites reaches as high as 69% after 5000 CV-cycles at a high voltage range of 0.8–1.23 V, in contrast to 19% for that of the Pt-graphene oxide composites. The excellent durability of the Pt-CeO2 nanocubes-graphene oxide catalyst is attributed to the free radical scavenging activity of CeO2, which significantly slows down the chemical degradation of Nafion binder in catalytic layers, and then alleviates the decay of Pt catalysts, resulting in the excellent cycle life of Pt-CeO2-graphene oxide nanocomposite catalysts. Additionally, the performance of single cell assembled with Nafion 211 membrane and Pt-CeO2-graphene oxide catalysts with different CeO2 contents in the cathode as well as the Pt-C catalysts in the anode are also recorded and discussed in this study. PMID:25491655

  10. Process for preparing a liquid fuel composition

    DOEpatents

    Singerman, Gary M.

    1982-03-16

    A process for preparing a liquid fuel composition which comprises liquefying coal, separating a mixture of phenols from said liquefied coal, converting said phenols to the corresponding mixture of anisoles, subjecting at least a portion of the remainder of said liquefied coal to hydrotreatment, subjecting at least a portion of said hydrotreated liquefied coal to reforming to obtain reformate and then combining at least a portion of said anisoles and at least a portion of said reformate to obtain said liquid fuel composition.

  11. Biomass conversion processes for energy and fuels

    NASA Astrophysics Data System (ADS)

    Sofer, S. S.; Zaborsky, O. R.

    The book treats biomass sources, promising processes for the conversion of biomass into energy and fuels, and the technical and economic considerations in biomass conversion. Sources of biomass examined include crop residues and municipal, animal and industrial wastes, agricultural and forestry residues, aquatic biomass, marine biomass and silvicultural energy farms. Processes for biomass energy and fuel conversion by direct combustion (the Andco-Torrax system), thermochemical conversion (flash pyrolysis, carboxylolysis, pyrolysis, Purox process, gasification and syngas recycling) and biochemical conversion (anaerobic digestion, methanogenesis and ethanol fermentation) are discussed, and mass and energy balances are presented for each system.

  12. SOFC system with integrated catalytic fuel processing

    NASA Astrophysics Data System (ADS)

    Finnerty, Caine; Tompsett, Geoff. A.; Kendall, Kevin; Ormerod, R. Mark

    In recent years, there has been much interest in the development of solid oxide fuel cell technology operating directly on hydrocarbon fuels. The development of a catalytic fuel processing system, which is integrated with the solid oxide fuel cell (SOFC) power source is outlined here. The catalytic device utilises a novel three-way catalytic system consisting of an in situ pre-reformer catalyst, the fuel cell anode catalyst and a platinum-based combustion catalyst. The three individual catalytic stages have been tested in a model catalytic microreactor. Both temperature-programmed and isothermal reaction techniques have been applied. Results from these experiments were used to design the demonstration SOFC unit. The apparatus used for catalytic characterisation can also perform in situ electrochemical measurements as described in previous papers [C.M. Finnerty, R.H. Cunningham, K. Kendall, R.M. Ormerod, Chem. Commun. (1998) 915-916; C.M. Finnerty, N.J. Coe, R.H. Cunningham, R.M. Ormerod, Catal. Today 46 (1998) 137-145]. This enabled the performance of the SOFC to be determined at a range of temperatures and reaction conditions, with current output of 290 mA cm -2 at 0.5 V, being recorded. Methane and butane have been evaluated as fuels. Thus, optimisation of the in situ partial oxidation pre-reforming catalyst was essential, with catalysts producing high H 2/CO ratios at reaction temperatures between 873 K and 1173 K being chosen. These included Ru and Ni/Mo-based catalysts. Hydrocarbon fuels were directly injected into the catalytic SOFC system. Microreactor measurements revealed the reaction mechanisms as the fuel was transported through the three-catalyst device. The demonstration system showed that the fuel processing could be successfully integrated with the SOFC stack.

  13. An integrated process for hydrogen-rich gas production from cotton stalks: The simultaneous gasification of pyrolysis gases and char in an entrained flow bed reactor.

    PubMed

    Chen, Zhiyuan; Zhang, Suping; Chen, Zhenqi; Ding, Ding

    2015-12-01

    An integrated process (pyrolysis, gas-solid simultaneous gasification and catalytic steam reforming) was utilized to produce hydrogen-rich gas from cotton stalks. The simultaneous conversion of the pyrolysis products (char and pyrolysis gases) was emphatically investigated using an entrained flow bed reactor. More carbon of char is converted into hydrogen-rich gas in the simultaneous conversion process and the carbon conversion is increased from 78.84% to 92.06% compared with the two stages process (pyrolysis and catalytic steam reforming). The distribution of tar components is also changed in this process. The polycyclic aromatic compounds (PACs) of tar are converted into low-ring compounds or even chain compounds due to the catalysis of char. In addition, the carbon deposition yield over NiO/MgO catalyst in the steam reforming process is approximately 4 times higher without the simultaneous process. The potential H2 yield increases from 47.71 to 78.19g/kg cotton stalks due to the simultaneous conversion process. PMID:26433156

  14. Exploring Entrainment Patterns of Human Emotion in Social Media.

    PubMed

    He, Saike; Zheng, Xiaolong; Zeng, Daniel; Luo, Chuan; Zhang, Zhu

    2016-01-01

    Emotion entrainment, which is generally defined as the synchronous convergence of human emotions, performs many important social functions. However, what the specific mechanisms of emotion entrainment are beyond in-person interactions, and how human emotions evolve under different entrainment patterns in large-scale social communities, are still unknown. In this paper, we aim to examine the massive emotion entrainment patterns and understand the underlying mechanisms in the context of social media. As modeling emotion dynamics on a large scale is often challenging, we elaborate a pragmatic framework to characterize and quantify the entrainment phenomenon. By applying this framework on the datasets from two large-scale social media platforms, we find that the emotions of online users entrain through social networks. We further uncover that online users often form their relations via dual entrainment, while maintain it through single entrainment. Remarkably, the emotions of online users are more convergent in nonreciprocal entrainment. Building on these findings, we develop an entrainment augmented model for emotion prediction. Experimental results suggest that entrainment patterns inform emotion proximity in dyads, and encoding their associations promotes emotion prediction. This work can further help us to understand the underlying dynamic process of large-scale online interactions and make more reasonable decisions regarding emergency situations, epidemic diseases, and political campaigns in cyberspace. PMID:26953692

  15. Exploring Entrainment Patterns of Human Emotion in Social Media

    PubMed Central

    Luo, Chuan; Zhang, Zhu

    2016-01-01

    Emotion entrainment, which is generally defined as the synchronous convergence of human emotions, performs many important social functions. However, what the specific mechanisms of emotion entrainment are beyond in-person interactions, and how human emotions evolve under different entrainment patterns in large-scale social communities, are still unknown. In this paper, we aim to examine the massive emotion entrainment patterns and understand the underlying mechanisms in the context of social media. As modeling emotion dynamics on a large scale is often challenging, we elaborate a pragmatic framework to characterize and quantify the entrainment phenomenon. By applying this framework on the datasets from two large-scale social media platforms, we find that the emotions of online users entrain through social networks. We further uncover that online users often form their relations via dual entrainment, while maintain it through single entrainment. Remarkably, the emotions of online users are more convergent in nonreciprocal entrainment. Building on these findings, we develop an entrainment augmented model for emotion prediction. Experimental results suggest that entrainment patterns inform emotion proximity in dyads, and encoding their associations promotes emotion prediction. This work can further help us to understand the underlying dynamic process of large-scale online interactions and make more reasonable decisions regarding emergency situations, epidemic diseases, and political campaigns in cyberspace. PMID:26953692

  16. Nd1.8Ce0.2CuO4+δ:Ce0.9Gd0.1O2-δ as a composite cathode for intermediate-temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Khandale, A. P.; Bhoga, S. S.

    2014-12-01

    The (100 - x)Nd1.8Ce0.2CuO4+δ:(x)Ce0.9Gd0.1O2-δ (x = 00, 10, 20 and 30 vol.%) composite systems are obtained by impregnating a stoichiometric solution of cerium and gadolinium nitrates followed by sintering at 900 °C for 4 h. Impregnating the Ce0.9Gd0.1O2-δ not only inhibits the growth of the host Nd1.8Ce0.2CuO4+δ grains during sintering but also enlarges the oxygen reduction reaction zone by introducing a nanosized phase that is ionically conductive, which significantly decreases the electrode polarization resistance of the composite cathode. A minimum polarization resistance value of 0.23 ± 0.02 Ω cm2 is obtained at 700 °C for a (80)Nd1.8Ce0.2CuO4+δ:(20)Ce0.9Gd0.1O2-δ composite cathode, and this value is attributed to the optimal dispersion into the porous Nd1.8Ce0.2CuO4+δ matrix. The impedance spectra are modeled using an electrical equivalent model that consists of a mid-frequency ZR1 -CPE circuit (parallel combination of R1 and constant phase element (CPE)) and a low-frequency Gerischer impedance. The Gerischer impedance decreases significantly when Ce0.9Gd0.1O2-δ infiltrates the Nd1.8Ce0.2CuO4+δ matrix. The oxygen partial pressure-dependent polarization study suggests a medium-frequency response, which is due to charge transfer step; however, the low-frequency response corresponds to the non-charge transfer oxygen adsorption-desorption and the diffusion process during the overall oxygen reduction reaction process.

  17. Alternative Fuel for Portland Cement Processing

    SciTech Connect

    Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; Venkatasubramanian, Vignesh; Stephen, Giles

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

  18. Ultra-Deep Adsorptive Desulfurization of Light-Irradiated Diesel Fuel over Supported TiO2-CeO2 Adsorbents

    SciTech Connect

    Xiao, Jing; Wang, Xiaoxing; Chen, Yongsheng; Fujii, Mamoru; Song, Chunshan

    2014-02-13

    This study investigates ultra-deep adsorptive desulfurization (ADS) from light-irradiated diesel fuel over supported TiO2CeO2 adsorbents. A 30-fold higher desulfurization capacity of 95 mL of fuel per gram of adsorbent (mL-F/g-sorb) or 1.143 mg of sulfur per gram of adsorbent (mg-S/g-sorb) was achieved from light-irradiated fuel over the original low-sulfur fuel containing about 15 ppm by weight (ppmw) of sulfur. The sulfur species on spent TiO2CeO2/MCM-48 adsorbent was identified by sulfur K-edge XANES as sulfones and the adsorption selectivity to different compounds tested in a model fuel decreases in the order of indole > dibenzothiophenesulfone → dibenzothiophene > 4-methyldibenzothiophene > benzothiophene > 4,6-dimethyldibenzothiophene > phenanthrene > 2-methylnaphthalene ~ fluorene > naphthalene. The results suggest that during ADS of light-irradiated fuel, the original sulfur species were chemically transformed to sulfones, resulting in the significant increase in desulfurization capacity. For different supports for TiO2–CeO2 oxides, the ADS capacity increases with a decrease in the point of zero charge (PZC) value; for silica-supported TiO2CeO2 oxides (the lowest PZC value of 2–4) with different surface areas, the ADS capacity increases monotonically with increasing surface area. The supported TiO2CeO2/MCM-48 adsorbent can be regenerated using oxidative air treatment. The present study provides an attractive new path to achieve ultraclean fuel more effectively.

  19. Nanoporous silver cathode surface treated by atomic layer deposition of CeO(x) for low-temperature solid oxide fuel cells.

    PubMed

    Neoh, Ke Chean; Han, Gwon Deok; Kim, Manjin; Kim, Jun Woo; Choi, Hyung Jong; Park, Suk Won; Shim, Joon Hyung

    2016-05-01

    We evaluated the performance of solid oxide fuel cells (SOFCs) with a 50 nm thin silver (Ag) cathode surface treated with cerium oxide (CeO(x)) by atomic layer deposition (ALD). The performances of bare and ALD-treated Ag cathodes were evaluated on gadolinia-doped ceria (GDC) electrolyte supporting cells with a platinum (Pt) anode over 300 °C-450 °C. Our work confirms that ALD CeO(x) treatment enhances cathodic performance and thermal stability of the Ag cathode. The performance difference between cells using a Ag cathode optimally treated with an ALD CeO(x) surface and a reference Pt cathode is about 50% at 450 °C in terms of fuel cell power output in our experiment. The bare Ag cathode completely agglomerated into islands during fuel cell operation at 450 °C, while the ALD CeO(x) treatment effectively protects the porosity of the cathode. We also discuss the long-term stability of ALD CeO(x)-treated Ag cathodes related to the microstructure of the layers. PMID:27008979

  20. Nanoporous silver cathode surface treated by atomic layer deposition of CeO x for low-temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Chean Neoh, Ke; Han, Gwon Deok; Kim, Manjin; Kim, Jun Woo; Jong Choi, Hyung; Park, Suk Won; Shim, Joon Hyung

    2016-05-01

    We evaluated the performance of solid oxide fuel cells (SOFCs) with a 50 nm thin silver (Ag) cathode surface treated with cerium oxide (CeO x ) by atomic layer deposition (ALD). The performances of bare and ALD-treated Ag cathodes were evaluated on gadolinia-doped ceria (GDC) electrolyte supporting cells with a platinum (Pt) anode over 300 °C-450 °C. Our work confirms that ALD CeO x treatment enhances cathodic performance and thermal stability of the Ag cathode. The performance difference between cells using a Ag cathode optimally treated with an ALD CeO x surface and a reference Pt cathode is about 50% at 450 °C in terms of fuel cell power output in our experiment. The bare Ag cathode completely agglomerated into islands during fuel cell operation at 450 °C, while the ALD CeO x treatment effectively protects the porosity of the cathode. We also discuss the long-term stability of ALD CeO x -treated Ag cathodes related to the microstructure of the layers.

  1. Entrainment across density interfaces

    NASA Astrophysics Data System (ADS)

    Sanchez, M. A.; Carrillo, A.; Mahjoub, O. B.

    2010-05-01

    The structure of non-homogeneous turbulence affected by stratification and rotation is investigated both by means of laboratory and numerical experiments. The experiments investigate zero mean flow across a stably stratified density interface and are used to quantify the entrainment, the mixing efficiency and different types of dominant instability and the topological aspects of the turbulent cascades detected both horizontally and vertically [1,2]. Grid turbulence in a rotating stratified two layer system is measured with PIV as well as with sonic velocimetry. Observations of the horizontal and vertical velocity energy spectra as well as the structure functions are used to estimate local mixedness, entrainment and intermittency [3,4]. The method of estimation of the average eddy diffusivity from the time series images of a sharp density interface marked by fluoresceine also take anisotropy into account. but on the long run, horizontal ( and 2D type flow such as [5]) flow directions will average out so using a single integral length scale defined in Sanchez and Redondo(1998) varying in height will be enough together with the internal frequency. The method of calculating vertical fluxes in time allows to estimate different intermittency parameters as a function of local instability e.g. Kelvin/Helmholtz, Rayleigh-Taylor or Holbmoe[6-8]. Different concentration interfaces show different fractal dimensions, that are also a power function of the local Richardson number, this may be due to different levels of intermittency and thus different spectra, which are not necessarily inertial nor in equilibrium [8,9]. [1] Sanchez M.A. and Redondo J.M.Observations from Grid Stirred Turbulence. Applied Scientific Research 59, 191-204. 1998. [2] Redondo, J.M. and Cantalapiedra I.R. Mixing in Horizontally Heterogeneous Flows . Jour. Flow Turbulence and Combustion. 51, 217-222. 1993. [3] Castilla R, Redondo J.M., Gamez P.J., Babiano A. Coherent vortices and Lagrangian Dynamics in 2D

  2. Physiology of circadian entrainment.

    PubMed

    Golombek, Diego A; Rosenstein, Ruth E

    2010-07-01

    Mammalian circadian rhythms are controlled by endogenous biological oscillators, including a master clock located in the hypothalamic suprachiasmatic nuclei (SCN). Since the period of this oscillation is of approximately 24 h, to keep synchrony with the environment, circadian rhythms need to be entrained daily by means of Zeitgeber ("time giver") signals, such as the light-dark cycle. Recent advances in the neurophysiology and molecular biology of circadian rhythmicity allow a better understanding of synchronization. In this review we cover several aspects of the mechanisms for photic entrainment of mammalian circadian rhythms, including retinal sensitivity to light by means of novel photopigments as well as circadian variations in the retina that contribute to the regulation of retinal physiology. Downstream from the retina, we examine retinohypothalamic communication through neurotransmitter (glutamate, aspartate, pituitary adenylate cyclase-activating polypeptide) interaction with SCN receptors and the resulting signal transduction pathways in suprachiasmatic neurons, as well as putative neuron-glia interactions. Finally, we describe and analyze clock gene expression and its importance in entrainment mechanisms, as well as circadian disorders or retinal diseases related to entrainment deficits, including experimental and clinical treatments. PMID:20664079

  3. DEVELOPMENT OF SUPERIOR ENTRAINMENT SEPARATORS

    EPA Science Inventory

    An experimental and theoretical program was carried out to develop an improved design for entrainment separators for scrubbers. The problems of separation efficiency, suspended solids deposition and plugging of the entrainment separator were of primary concern. A pilot scale entr...

  4. Effects of annealing process on magnetic properties and structures of Nd-Pr-Ce-Fe-B melt-spun powders

    NASA Astrophysics Data System (ADS)

    Pei, Kun; Lin, Min; Yan, Aru; Zhang, Xing

    2016-05-01

    The effects of annealing process on magnetic properties and structures of Nd-Pr-Ce-Fe-B melt-spun powders have been investigated. The magnetic properties improve a lot when the annealing temperature is 590-650 °C and the annealing time exceeds 1 min. The magnetic properties is stable when the annealing time is 590-650 °C. The powders contains obvious grains when the annealing time is only 1 min, while the grains grow up obviously, leading to the decrease of Br and (BH)max, when the annealing time is more than 9 min. The Hcj changes little for different annealing time. The cooling rate also affects the magnetic properties of powders with different Ce-content. Faster cooling rate is favorable to improve magnetic properties with low Ce-content powders, while high Ce-content powders need slower cooling rate.

  5. Digital processing of signals from LaBr3:Ce scintillation detectors

    NASA Astrophysics Data System (ADS)

    Nakhostin, M.; Podolyak, Zs; Regan, P. H.

    2014-12-01

    In this paper, we report on the results of digital signal processing of LaBr3(Ce) detectors. The photomultiplier (PMT) output signals from two cylindrical LaBr3(Ce) detectors (1.5'' diameter and 2'' tall) were directly digitized with an ultrafast digitizer (sampling rate up to 4 GSample/s and 10-bits resolution) and the energy and timing information were extracted through offline analysis of the pulses. It is shown that at high sampling rates (4 GS/s) a simple integration of pulses is sufficient to reproduce the analogue energy resolution of the detectors (3.5% at 662 keV energy) and by employing a digital version of constant-fraction discrimination (CFD) timing a time resolution of 240 ps (FWHM) is achieved at the energy lines of 60Co. The effects of pulse sampling rate were studied, indicating a degradation of the performance of the detectors with reducing the pulse sampling rate. In particular, it was found that at sampling rates below 1 GS/s, the digital timing can be limited by the aliasing error. By using an anti-aliasing filter, a time resolution of 375 ps (FWHM) and an energy resolution of 3.5% at 662 keV were achieved with a sampling rate of 500 MS/s.

  6. The effects of physicochemical properties of CeO2 nanoparticles on toxicity to soil denitrification processes

    NASA Astrophysics Data System (ADS)

    Dahle, Jessica Teague

    The studies presented in this thesis identify the impact of NP CeO 2 on soil denitrifying microbial communities and reveal that physical and chemical characteristics including particle size, speciation, concentration, pH, and presence of ligands are key to predicting environmental fate and reactivity of NP CeO2 in the soil. A review of the literature in Chapter 1 revealed a widespread lack of toxicological information for soil exposures to NP CeO2. Soil denitrifying bacteria are a keystone species because they serve an important role in the global nitrogen cycle controlling the atmospheric nitrogen input. Soil denitrifiers are important to this study because the reducing conditions during denitrification could induce phase transformation of Ce(IV) to Ce(III), potentially influencing the toxicity of Ce. Cerium is well known for being the only lanthanide that is thermodynamically stable in both the trivalent and tetravalent state in low temperature geochemical environments. Using well characterized NP Ce(IV)O 2 as well as bulk soluble Ce(III), batch denitrification experiments were conducted to evaluate the toxicity of Ce species to the denitrifying community in a Toccoa sandy loam soil. The statistical analysis on the antimicrobial effect on soil denitrifiers was conducted using both steady-state evaluation and zero-order kinetic models in order to compare the toxicity of the Ce(III) species to the NPs. These studies, presented in Chapter 3, show that soluble Ce(III) is far more toxic than Ce(IV)O2 NPs when an equal total concentration of Ce is used, though both species exhibit toxicity to the denitrifiers via statistically significant inhibition of soil denitrification processes. Particle-size dependent toxicity, species-dependent toxicity, and concentration-dependent toxicity were all observed in this study for both the steady-state and the kinetic evaluations. The possibility of toxicity enhancement and diminishment via dissolution and ligand complexation

  7. Distributed generation - the fuel processing example

    SciTech Connect

    Victor, R.A.; Farris, P.J.; Maston, V.

    1996-12-31

    The increased costs of transportation and distribution are leading many commercial and industrial firms to consider the on-site generation for energy and other commodities used in their facilities. This trend has been accelerated by the development of compact, efficient processes for converting basic raw materials into finished services at the distributed sites. Distributed generation with the PC25{trademark} fuel cell power plant is providing a new cost effective technology to meet building electric and thermal needs. Small compact on-site separator systems are providing nitrogen and oxygen to many industrial users of these gases. The adaptation of the fuel processing section of the PC25 power plant for on-site hydrogen generation at industrial sites extends distributed generation benefits to the users of industrial hydrogen.

  8. Ionic Conduction and Fuel Cell Performance of Ba0.97Ce0.8Ho0.2O3-α Ceramic

    NASA Astrophysics Data System (ADS)

    Qiu, Li-gan

    2006-08-01

    The perovskite-type-oxide solid solution Ba0.97Ce0.8Ho0.2O3-α was prepared by high temperature solid-state reaction and its single-phase character was confirmed by X-ray diffraction. The ionic conduction of the sample was investigated using electrical methods at elevated temperatures, and the performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured, which were compared with those of BaCe0.8Ho0.2O3-α. In wet hydrogen, BaCe0.8Ho0.2O3-α almost exhibits pure protonic conduction at 600-1000 °C, and its protonic transport number is 1 at 600-900 °C and 0.99 at 1000 °C. Similarly, Ba0.97Ce0.8Ho0.2O3-α exhibits pure protonic conduction with the protonic transport number of 1 at 600-700 °C, but its protonic conduction is slightly lower than that of BaCe0.8Ho0.2O3-α, and the protonic transport number are 0.99-0.96 at 800-1000 °C. In wet air, the two samples both show low protonic and oxide ionic conduction. For Ba0.97Ce0.8Ho0.2O3-α, the protonic and oxide ionic transport numbers are 0.01-0.11 and 0.30-0.31 respectively, and for BaCe0.8Ho0.2O3-α, 0.01-0.09 and 0.27-0.33 respectively. Ionic conductivities of Ba0.97Ce0.8Ho0.2O3-α are higher than those of BaCe0.8Ho0.2O3-α under wet hydrogen and wet air. The performance of the fuel cell using Ba0.97Ce0.8Ho0.2O3-α as solid electrolyte is better than that of BaCe0.8Ho0.2O3-α. At 1000 °C, its maximum short-circuit current density and power output density are 465 mA/cm2 and 112 mW/cm2, respectively.

  9. Data processing and initial results from the CE-3 Extreme Ultraviolet Camera

    NASA Astrophysics Data System (ADS)

    Feng, Jian-Qing; Liu, Jian-Jun; He, Fei; Yan, Wei; Ren, Xin; Tan, Xu; He, Ling-Ping; Chen, Bo; Zuo, Wei; Wen, Wei-Bin; Su, Yan; Zou, Yong-Liao; Li, Chun-Lai

    2014-12-01

    The Extreme Ultraviolet Camera (EUVC) onboard the Chang'e-3 (CE-3) lander is used to observe the structure and dynamics of Earth's plasmasphere from the Moon. By detecting the resonance line emission of helium ions (He+) at 30.4 nm, the EUVC images the entire plasmasphere with a time resolution of 10 min and a spatial resolution of about 0.1 Earth radius (RE) in a single frame. We first present details about the data processing from EUVC and the data acquisition in the commissioning phase, and then report some initial results, which reflect the basic features of the plasmasphere well. The photon count and emission intensity of EUVC are consistent with previous observations and models, which indicate that the EUVC works normally and can provide high quality data for future studies.

  10. Complete Oxidation of Benzene Over CuO-CeO2 Catalysts Prepared Using Different Process.

    PubMed

    Jung, Won Young; Hong, Seong-Soo

    2016-05-01

    Catalytic combustion of benzene over CuO-CeO2 mixed oxides has been investigated. The CuO-CeO2 mixed oxides were prepared using various methods and characterized by XRD, BET and TPR. For the CuO-CeO2 catalysts with a Cu/(Cu + Ce) molar ratio of more than 0.5, highly dispersed copper oxide species were shown at 2θ = 35.5 degrees and 38.8 degrees. The CuO-CeO2 catalyst prepared using co-precipitation method showed the highest activity. In addition, the highest activity is shown on Cu0.35 (the index denotes the molar ratio Cu/(Cu + Ce)) sample and then it decreases on Cu0.5 and Cu0.6 samples. PMID:27483793

  11. Pyroprocess for processing spent nuclear fuel

    DOEpatents

    Miller, William E.; Tomczuk, Zygmunt

    2002-01-01

    This is a pyroprocess for processing spent nuclear fuel. The spent nuclear fuel is chopped into pieces and placed in a basket which is lowered in to a liquid salt solution. The salt is rich in ZrF.sub.4 and containing alkali or alkaline earth fluorides, and in particular, the salt chosen was LiF-50 mol % ZrF.sub.4 with a eutectic melting point of 500.degree. C. Prior to lowering the basket, the salt is heated to a temperature of between 550.degree. C. and 700.degree. C. in order to obtain a molten solution. After dissolution the oxides of U, Th, rare earth and other like oxides, the salt bath solution is subject to hydro-fluorination to remove the oxygen and then to a fluorination step to remove U as gaseous UF.sub.6. In addition, after dissolution, the basket contains PuO.sub.2 and undissolved parts of the fuel rods, and the basket and its contents are processed to remove the Pu.

  12. Mesler entrainment in alcohols

    NASA Astrophysics Data System (ADS)

    Saylor, J. R.; Sundberg, R. K.

    2012-11-01

    When a drop impacts a flat surface of the same liquid at an intermediate velocity, the impact can result in the formation of a very large number of very small bubbles. At lower velocities, drops bounce or float, and at larger velocities a single bubble forms, or there is a splash. The formation of large numbers of small bubbles during intermediate velocity impacts is termed Mesler entrainment and its controlling mechanism is poorly understood. Existing research has shown that Mesler entrainment is highly irreproducible when water is the working fluid, and very reproducible when silicone oil is the working fluid. Whether this is because water is problematic, or silicone oil is uniquely well-suited, is unclear. To answer this question, experiments were conducted using three different alcohols. The results of these experiments were very reproducible for all alcohols tested, suggesting that there is something unique about water which accounts for its lack of reproducibility. The data from these experiments were also used to develop a dimensionless group that quantifies the conditions under which Mesler entrainment occurs. This dimensionless group is used to provide insight into the mechanism of this unique method of bubble formation.

  13. MEASUREMENT OF ENTRAINED ORGANIC DROPLET SIZES AND TOTAL CONCENTRATION FOR AQUEOUS STREAMS FROM THE CAUSTIC-SIDE SOLVENT EXTRACTION PROCESS

    SciTech Connect

    Nash, C; Samuel Fink, S; Michael Restivo, M; Dan Burns, D; Wallace Smith, W; S Crump, S; Zane Nelson, Z; Thomas Peters, T; Fernando Fondeur, F; Michael Norato, M

    2007-02-01

    The Modular Caustic-Side Solvent Extraction Unit (MCU) and the Salt Waste Processing Facility will remove radioactive cesium from Savannah River Site supernate wastes using an organic solvent system. Both designs include decanters and coalescers to reduce carryover of organic solvent droplets. Savannah River National Laboratory personnel conducted experimental demonstrations using a series of four 2-cm centrifugal contactors. They also examined organic carryover during operation of a CINC (Costner Industries Nevada Corporation) V-5 contactor under prototypical conditions covering the range of expected MCU operation. This report details the findings from those studies and the implications on design for the MCU.

  14. Modeling of a CeO2 thermochemistry reduction process for hydrogen production by solar concentrated energy

    NASA Astrophysics Data System (ADS)

    Valle-Hernández, Julio; Romero-Paredes, Hernando; Arancibia-Bulnes, Camilo A.; Villafan-Vidales, Heidi I.; Espinosa-Paredes, Gilberto

    2016-05-01

    In this paper the simulation of the thermal reduction for hydrogen production through the decomposition of cerium oxide is presented. The thermochemical cycle for hydrogen production consists of the endothermic reduction of CeO2 at high temperature, where concentrated solar energy is used as a source of heat; and of the subsequent steam hydrolysis of the resulting cerium oxide to produce hydrogen. For the thermochemical process, a solar reactor prototype is proposed; consisting of a cubic receptacle made of graphite fiber thermally insulated. Inside the reactor a pyramidal arrangement with nine tungsten pipes is housed. The pyramidal arrangement is made respect to the focal point where the reflected energy is concentrated. The solar energy is concentrated through the solar furnace of high radiative flux. The endothermic step is the reduction of the cerium oxide to lower-valence cerium oxide, at very high temperature. The exothermic step is the hydrolysis of the cerium oxide (III) to form H2 and the corresponding initial cerium oxide made at lower temperature inside the solar reactor. For the modeling, three sections of the pipe where the reaction occurs were considered; the carrier gas inlet, the porous medium and the reaction products outlet. The mathematical model describes the fluid mechanics; mass and energy transfer occurring therein inside the tungsten pipe. Thermochemical process model was simulated in CFD. The results show a temperature distribution in the solar reaction pipe and allow obtaining the fluid dynamics and the heat transfer within the pipe. This work is part of the project "Solar Fuels and Industrial Processes" from the Mexican Center for Innovation in Solar Energy (CEMIE-Sol).

  15. Y0.08Sr0.88TiO3-CeO2 composite as a diffusion barrier layer for stainless-steel supported solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Kim, Kun Joong; Kim, Sun Jae; Choi, Gyeong Man

    2016-03-01

    A new diffusion barrier layer (DBL) is proposed for solid oxide fuel cells (SOFCs) supported on stainless-steel where DBL prevents inter-diffusion of atoms between anode and stainless steel (STS) support during fabrication and operation of STS-supported SOFCs. Half cells consisting of dense yttria-stabilized zirconia (YSZ) electrolyte, porous Ni-YSZ anode layer, and ferritic STS support, with or without Y0.08Sr0.88TiO3-CeO2 (YST-CeO2) composite DBL, are prepared by tape casting and co-firing at 1250 and 1350 °C, respectively, in reducing (H2) atmosphere. The porous YST-CeO2 layer (t ∼ 60 μm) blocks inter-diffusion of Fe and Ni, and captures the evaporated Cr during cell fabrication (1350 °C). The cell with DBL and La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode achieved a maximum power density of ∼220 mW cm-2 which is stable at 700 °C. In order to further improve the power performance, Ni coarsening in anode during co-firing must be prevented or alternative anode which is resistive to coarsening is suggested. This study demonstrates that the new YST-CeO2 layer is a promising as a DBL for stainless-steel-supported SOFCs fabricated with co-firing process.

  16. Cellular processing of copper-67-labeled monoclonal antibody chCE7 by human neuroblastoma cells.

    PubMed

    Novak-Hofer, I; Amstutz, H P; Mäcke, H R; Schwarzbach, R; Zimmermann, K; Morgenthaler, J J; Schubiger, P A

    1995-01-01

    Monoclonal antibody chCE7, an internalizing neuroblastoma-specific chimeric antibody, was derivatized with the macrocyclic amine ligand 4-[(1,4,8,11-tetraazacyclotetradec-1-yl)-methyl] benzoic acid tetrahydrochloride and labeled with the potential therapeutic nuclide 67Cu. Using pulse labeling and an acid elution endocytosis assay, 67Cu-chCE7 was found to be internalized into human neuroblastoma (SKN-AS) cells at a similar rate and to a similar extent as 125I-labeled chCE7. Uptake of 67Cu-chCE7 and 125I-chCE7 into the acid stable (intracellular) pool proceeded with similar kinetics during the first 2 h of internalization. However, in contrast to 125I-chCE7-loaded cells, at later times intracellular radioactivity kept increasing in the case of 67Cu-chCE7-loaded cells. It was shown that this effect is due to the intracellular accumulation of a low M(r) degradation product consisting of the 67Cu-4[(1,4,8,11-tetraazacyclotetradec-1-yl)-methyl] benzoic acid complex, possibly with a short peptide attached to it. Degradation of both 125I-chCE7 and 67Cu-chCE7 was inhibited by chloroquine, indicating endosomal or lysosomal degradation, and a 43,000 M(r) fragment was found to be the major high M(r) degradation product in both cases. Although at times between 4 and 6 h of internalization intracellular breakdown of 67Cu-chCE7 was found to proceed more slowly, the major difference between the two immunoconjugates resides in the prolonged cellular retention of the 67Cu-chCE7 metabolite. PMID:7805039

  17. Situ process for making multifunctional fuel additives

    SciTech Connect

    Carrier, R.C.; Allen, B.R.

    1984-02-28

    Disclosed is an in situ or ''one pot'' process for making a fuel additive comprising reacting an excess of at least one N-primary alkylalkylene diamine with maleic anhydride in the presence of from 20 to 36 weight percent of a mineral oil reaction diluent at a temperature ranging from ambient to about 225/sup 0/ F. and recovering a product containing a primary aliphatic hydrocarbon amino alkylene substituted asparagine, an N-primary alkylalkylene diamine in the reaction oil with the product having a by-product succinimide content not in excess of 1.0 weight percent, based on the weight of asparagine present.

  18. In Situ fuel processing in a microbial fuel cell.

    PubMed

    Bahartan, Karnit; Amir, Liron; Israel, Alvaro; Lichtenstein, Rachel G; Alfonta, Lital

    2012-09-01

    A microbial fuel cell (MFC) was designed in which fuel is generated in the cell by the enzyme glucoamylase, which is displayed on the surface of yeast. The enzyme digests starch specifically into monomeric glucose units and as a consequence enables further glucose oxidation by microorganisms present in the MFC anode. The oxidative enzyme glucose oxidase was coupled to the glucoamylase digestive enzyme. When both enzymes were displayed on the surface of yeast cells in a mixed culture, superior fuel-cell performance was observed in comparison with other combinations of yeast cells, unmodified yeast, or pure enzymes. The feasibility of the use of the green macroalgae Ulva lactuca in such a genetically modified MFC was also demonstrated. Herein, we report the performance of such fuel cells as a proof of concept for the enzymatic digestion of complex organic fuels in the anode of MFCs to render the fuel more available to microorganisms. PMID:22833422

  19. Insight into the structure and functional application of the Sr0.95Ce0.05CoO3-δ cathode for solid oxide fuel cells.

    PubMed

    Yang, Wei; Zhang, Huairuo; Sun, Chunwen; Liu, Lilu; Alonso, J A; Fernández-Díaz, M T; Chen, Liquan

    2015-04-01

    A new perovskite cathode, Sr0.95Ce0.05CoO3-δ, performs well for oxygen-reduction reactions in solid oxide fuel cells (SOFCs). We gain insight into the crystal structure of Sr1-xCexCoO3-δ (x = 0.05, 0.1) and temperature-dependent structural evolution of Sr0.95Ce0.05CoO3-δ by X-ray diffraction, neutron powder diffraction, and scanning transmission electron microscopy experiments. Sr0.9Ce0.1CoO3-δ shows a perfectly cubic structure (a = a0), with a large oxygen deficiency in a single oxygen site; however, Sr0.95Ce0.05CoO3-δ exhibits a tetragonal perovskite superstructure with a double c axis, defined in the P4/mmm space group, that contains two crystallographically different cobalt positions, with distinct oxygen environments. The structural evolution of Sr0.95Ce0.05CoO3-δ at high temperatures was further studied by in situ temperature-dependent NPD experiments. At 1100 K, the oxygen atoms in Sr0.95Ce0.05CoO3-δ show large and highly anisotropic displacement factors, suggesting a significant ionic mobility. The test cell with a La0.8Sr0.2Ga0.83Mg0.17O3-δ-electrolyte-supported (∼300 μm thickness) configuration yields peak power densities of 0.25 and 0.48 W cm(-2) at temperatures of 1023 and 1073 K, respectively, with pure H2 as the fuel and ambient air as the oxidant. The electrochemical impedance spectra evolution with time of the symmetric cathode fuel cell measured at 1073 K shows that the Sr0.95Ce0.05CoO3-δ cathode possesses superior ORR catalytic activity and long-term stability. Mixed ionic-electronic conduction properties of Sr0.95Ce0.05CoO3-δ account for its good performance as an oxygen-reduction catalyst. PMID:25756843

  20. Alternative fuels utilization and the automotive emission certification process

    SciTech Connect

    Not Available

    1980-03-01

    The Clean Air Act of 1977 requires that commercially offered automotive fuels and fuel additives be substantially similar to fuels used in certifying model year 1975 and later vehicles. Procedures for certifying that vehicles perform with emissions that meet the Clean Air Act specifications and the impact of this emissions certification process on the use of alternative fuels, such as alcohols, alcohol-gasoline blends and synthetic fuels, in highway vehicles is discussed. (LCL)

  1. Catalytic oxidation with Al-Ce-Fe-PILC as a post-treatment system for coffee wet processing wastewater.

    PubMed

    Sanabria, Nancy R; Peralta, Yury M; Montañez, Mardelly K; Rodríguez-Valencia, Nelson; Molina, Rafael; Moreno, Sonia

    2012-01-01

    The effluent from the anaerobic biological treatment of coffee wet processing wastewater (CWPW) contains a non-biodegradable compound that must be treated before it is discharged into a water source. In this paper, the wet hydrogen peroxide catalytic oxidation (WHPCO) process using Al-Ce-Fe-PILC catalysts was researched as a post-treatment system for CWPW and tested in a semi-batch reactor at atmospheric pressure and 25 °C. The Al-Ce-Fe-PILC achieved a high conversion rate of total phenolic compounds (70%) and mineralization to CO(2) (50%) after 5 h reaction time. The chemical oxygen demand (COD) of coffee processing wastewater after wet hydrogen peroxide catalytic oxidation was reduced in 66%. The combination of the two treatment methods, biological (developed by Cenicafé) and catalytic oxidation with Al-Ce-Fe-PILC, achieved a 97% reduction of COD in CWPW. Therefore, the WHPCO using Al-Ce-Fe-PILC catalysts is a viable alternative for the post-treatment of coffee processing wastewater. PMID:22907449

  2. Entrainment and mixing mechanism in monsoon clouds

    NASA Astrophysics Data System (ADS)

    Bera, Sudarsan; Prabhakaran, Thara; Pandithurai, Govindan; Brenguier, Jean-Louis

    2015-04-01

    Entrainment and consequent mixing impacts the cloud microphysical parameters and droplet size distribution (DSD) significantly which are very important for cloud radiative properties and the mechanism for first rain drop formation. The entrainment and mixing mechanisms are investigated in this study using in situ observations in warm cumulus clouds over monsoon region. Entrainment is discussed in the framework of the homogeneous and inhomogeneous mixing concepts and their effects on cloud droplet size distribution, number concentration, liquid water content and mean radius are described. The degree of homogeneity increases with droplet number concentration and adiabatic fraction, indicating homogeneous type mixing in the cloud core where dilution is less. Inhomogeneous mixing is found to be a dominating process at cloud edges where dilution is significant. Cloud droplet size distribution (DSD) is found to shift towards lower sizes during a homogeneous mixing event in the cloud core whereas spectral width of DSD decreases due to inhomogeneous mixing at cloud edges. Droplet size spectra suggests that largest droplets are mainly formed in the less diluted cloud core while diluted cloud edges have relatively smaller droplets, so that raindrop formation occurs mainly in the core of the cloud. The origin of the entrained parcels in deep cumulus clouds is investigated using conservative thermodynamical parameters. The entrained parcels originate from a level close to the observation level or slightly below through lateral edges. Cloud edges are significantly diluted due to entrainment of sub-saturated environmental air which can penetrate several hundred meters inside the cloud before it gets mixed completely with the cloud mass. Less diluted parcels inside the cloud core originates from a level much below the cloud base height. Penetrating downdraft from cloud top is seldom observed at the observation level and strong downdrafts may be attributed to in-cloud oscillation

  3. Stratocumulus cloud deepening through entrainment

    NASA Technical Reports Server (NTRS)

    Randall, D. A.

    1984-01-01

    Under a substantial range of realistic conditions, stratocumulus cloud top entrainment is noted to either deepen an existing cloud layer or produce clouds in an unsaturated mixed layer, though the entrained air is warmer and drier than the mixed-layer air. These results, which apply irrespective of entrainment rate-determining mechanism, imply that the cloud top entrainment instability discussed by Randall (1980) and Deardorff (1980) does not necessarily destroy a layer cloud. Examples are given which include soundings, marine layer data, and simulation results produced by the UCLA general circulation model.

  4. Flowerlike CeO2 microspheres coated with Sr2Fe1.5Mo0.5Ox nanoparticles for an advanced fuel cell

    NASA Astrophysics Data System (ADS)

    Liu, Yanyan; Tang, Yongfu; Ma, Zhaohui; Singh, Manish; He, Yunjuan; Dong, Wenjing; Sun, Chunwen; Zhu, Bin

    2015-07-01

    Flowerlike CeO2 coated with Sr2Fe1.5Mo0.5Ox (Sr-Fe-Mo-oxide) nanoparticles exhibits enhanced conductivity at low temperatures (300-600 oC), e.g. 0.12 S cm-1 at 600 oC, this is comparable to pure ceria (0.1 S cm-1 at 800 oC). Advanced single layer fuel cell was constructed using the flowerlike CeO2/Sr-Fe-Mo-oxide layer attached to a Ni-foam layer coated with the conducting transition metal oxide. Such fuel cell has yielded a peak power density of 802 mWcm-2 at 550 oC. The mechanism of enhanced conductivity and cell performance were analyzed. These results provide a promising strategy for developing advanced low-temperature SOFCs.

  5. Flowerlike CeO2 microspheres coated with Sr2Fe1.5Mo0.5Ox nanoparticles for an advanced fuel cell

    PubMed Central

    Liu, Yanyan; Tang, Yongfu; Ma, Zhaohui; Singh, Manish; He, Yunjuan; Dong, Wenjing; Sun, Chunwen; Zhu, Bin

    2015-01-01

    Flowerlike CeO2 coated with Sr2Fe1.5Mo0.5Ox (Sr-Fe-Mo-oxide) nanoparticles exhibits enhanced conductivity at low temperatures (300–600 oC), e.g. 0.12 S cm−1 at 600 oC, this is comparable to pure ceria (0.1 S cm−1 at 800 oC). Advanced single layer fuel cell was constructed using the flowerlike CeO2/Sr-Fe-Mo-oxide layer attached to a Ni-foam layer coated with the conducting transition metal oxide. Such fuel cell has yielded a peak power density of 802 mWcm−2 at 550 oC. The mechanism of enhanced conductivity and cell performance were analyzed. These results provide a promising strategy for developing advanced low-temperature SOFCs. PMID:26154917

  6. Process for the production and recovery of fuel values from coal

    DOEpatents

    Sass, Allan; McCarthy, Harry E.; Kaufman, Paul R.; Finney, Clement S.

    1982-01-01

    A method of pyrolyzing and desulfurizing coal in a transport reactor to recover volatile fuel values and hydrogen by heating particulate coal entrained in a carrier gas substantially free of oxygen to a pyrolysis temperature in a zone within three seconds.

  7. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_

    SciTech Connect

    G. A. Moore; F. J. Rice; N. E. Woolstenhulme; J-F. Jue; B. H. Park; S. E. Steffler; N. P. Hallinan; M. D. Chapple; M. C. Marshall; B. L. Mackowiak; C. R. Clark; B. H. Rabin

    2009-11-01

    Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).

  8. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY

    SciTech Connect

    Glenn A. Moore; Francine J. Rice; Nicolas E. Woolstenhulme; W. David SwanK; DeLon C. Haggard; Jan-Fong Jue; Blair H. Park; Steven E. Steffler; N. Pat Hallinan; Michael D. Chapple; Douglas E. Burkes

    2008-10-01

    Within the Reduced Enrichment for Research and Test Reactors (RERTR) program directed by the US Department of Energy (DOE), UMo fuel-foils are being developed in an effort to realize high density monolithic fuel plates for use in high-flux research and test reactors. Namely, targeted are reactors that are not amenable to Low Enriched Uranium (LEU) fuel conversion via utilization of high density dispersion-based fuels, i.e. 8-9 gU/cc. LEU conversion of reactors having a need for >8-9 gU/cc fuel density will only be possible by way of monolithic fuel forms. The UMo fuel foils under development afford fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. Two primary challenges have been established with respect to UMo monolithic fuel development; namely, fuel element fabrication and in-reactor fuel element performance. Both issues are being addressed concurrently at the Idaho National Laboratory. An overview is provided of the ongoing monolithic UMo fuel development effort at the Idaho National Laboratory (INL); including development of complex/graded fuel foils. Fabrication processes to be discussed include: UMo alloying and casting, foil fabrication via hot rolling, fuel-clad interlayer application via co-rolling and thermal spray processes, clad bonding via Hot Isostatic Pressing (HIP) and Friction Bonding (FB), and fuel plate finishing.

  9. Evaluation of gasification and gas-cleanup processes for use in molten-carbonate fuel-cell power plants

    SciTech Connect

    Vidt, E.J.; Jablonski, G.; Alvin, M.A.; Wenglarz, R.A.; Patel, P.

    1981-12-01

    This interim report satisfies the Task B requirement to define process configurations for systems suitable for supplying fuel to molten carbonate fuel cells (MCFC) in industrial and utility power plants. The configurations studied include entrained, fluidized-bed, gravitating-bed, and molten salt gasifiers, both air and oxygen blown. Desulfurization systems utilizing wet scrubbing processes, such as Selexol and Rectisol II, and dry sorbents, such as iron oxide and dolomite, were chosen for evaluation. Cleanup systems not chosen by DOE's MCFC contractors, General Electric and United Technologies, Inc., for their MCFC power plant work by virtue of the resource requirements of those systems for commercial development were chosen for detailed study in Tasks C and D of this contract. Such systems include Westinghouse fluidized-bed gasification, air and oxygen blown, Rockwell molten carbonate air-blown gasification, METC iron oxide desulfurization, and dolomitic desulfurization. In addition, for comparison, gasification systems such as the Texaco entrained and the British Gas/Lurgi slagging units, along with wet scrubbing by Rectisol II, have also been chosen for detailed study.

  10. Can cloud-top entrainment promote cloud growth?

    NASA Technical Reports Server (NTRS)

    Randall, D. A.

    1984-01-01

    The primary significance of Cloud Deepening through Entrainment (CDE) is that it can prevent the cloud top entrainment instability from destroying a cloud deck. Without suppressing the instability, CDE transforms it from a cloud destroyer to a cloud builder. The analysis does not depend on an entrainment hypothesis. Moreover, it is not restricted to PBL stratocumulus sheets. Stratiform clouds in the free atmosphere can be subject to CDE we need only reinterpret Ps as the pressure at the base of an elevated turbulent mixed layer. Modest departures from well mixedness will alter the results quantitatively but not qualitatively. Processes other than entrainment, such as surface evaporation, radiative cooling, and advection will often work with CDE to build a cloud layer; but of course they can also oppose CDE by reducing the relative humidity. If we make the weak assumption that the deepening of a cloud layer favors an increase in the cloud top entrainment rate (without specifying any particular functional relationship) we are led to speculate that CDE can cause runaway cloud growth, even in the absence of cloud top entrainment instability. through CDE entrainment leads to a deeper cloud, which leads to stronger entrainment.

  11. Overview of fuel processing options for polymer electrolyte fuel cell systems

    SciTech Connect

    Kumar, R.

    1995-12-31

    The polymer electrolyte fuel cell (PEFC) is being developed for use in heavy- and light-duty transportation applications. While this fuel cell has been used successfully in buses and vans with compressed hydrogen as the on-board fuel [1,2], the fuel cell system must incorporate fuel processing (reforming) for any other on-board fuel to produce the hydrogen or hydrogen-rich fuel gas to be fed to the fuel cell stack. This is true even for alternative methods of storing hydrogen, such as use of a metal hydride or liquefied hydrogen. The ``fuel processing`` needed to recover the hydrogen includes providing the heat of dissociation of the hydride and cooling the hydrogen to the temperature of the fuel cell stack. Discussed below are some of the options being considered for processing of on-board fuels (other than compressed hydrogen) to generate the fuel cell anode gas, and the effects of fuel processing on system design, efficiency, steady-state and dynamic performance, and other factors.

  12. Power plant intake entrainment analysis

    SciTech Connect

    Edinger, J.E.; Kolluru, V.S.

    2000-04-01

    Power plant condenser cooling water intake entrainment of fish eggs and larvae is becoming an issue in evaluating environmental impacts around the plants. Methods are required to evaluate intake entrainment on different types of water bodies. Presented in this paper is a derivation of the basic relationships for evaluating entrainment from the standing crop of fish eggs and larvae for different regions of a water body, and evaluating the rate of entrainment from the standing crop. These relationships are coupled with a 3D hydrodynamic and transport model that provides the currents and flows required to complete the entrainment evaluation. Case examples are presented for a simple river system, and for the more complex Delaware River Estuary with multiple intakes. Example evaluations are made for individual intakes, and for the cumulative impacts of multiple intakes.

  13. The entraining moist boundary layer

    NASA Technical Reports Server (NTRS)

    Randall, D. A.

    1978-01-01

    A unified theory of entrainment into the planetary boundary layer is presented. It is assumed that the rates of buoyant and shear production of turbulence kinetic energy can be determined in terms of the entrainment mass flux. An expression is derived from the conservation law for turbulence kinetic energy, which, with the introduction of an empirical parameter, can be used together with a second relation between turbulence kinetic energy and the turbulence velocity scale to obtain the mass entrainment flux. The theory provides descriptions of storage-limited entrainment, buoyancy-limited entrainment into a clear mixed layer, and shallowing. It has been incorporated into a simulation of Day 33 of the Wangara experiment using a simple mixed layer model.

  14. Single-step process to prepare CeO2 nanotubes with improved catalytic activity.

    PubMed

    González-Rovira, Leandro; Sánchez-Amaya, José M; López-Haro, Miguel; del Rio, Eloy; Hungría, Ana B; Midgley, Paul; Calvino, José J; Bernal, Serafín; Botana, F Javier

    2009-04-01

    CeO(2) nanotubes have been grown electrochemically using a porous alumina membrane as a template. The resulting material has been characterized by means of scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy, high-angle annular dark-field scanning transmission electron microscopy tomography, high-resolution electron microscopy (HREM), and electron energy loss spectroscopy. According to SEM, the outer diameter of the nanotubes corresponds to the pore size (200 nm) of the alumina membrane, and their length ranges between 30 and 40 microm. HREM images have revealed that the width of the nanotube walls is about 6 nm. The catalytic activity of these novel materials for the CO oxidation reaction is compared to that of a polycrystalline powder CeO(2) sample prepared by a conventional route. The activity of the CeO(2) nanotubes is shown to be in the order of 400 times higher per gram of oxide at 200 degrees C (77.2 x 10(-2) cm(3) CO(2) (STP)/(gxs) for the nanotube-shaped CeO(2) and 0.16 x 10(-2) cm(3) CO(2) (STP)/(gxs) for the powder CeO(2)). PMID:19245236

  15. Process for producing fluid fuel from coal

    DOEpatents

    Hyde, Richard W.; Reber, Stephen A.; Schutte, August H.; Nadkarni, Ravindra M.

    1977-01-01

    Process for producing fluid fuel from coal. Moisture-free coal in particulate form is slurried with a hydrogen-donor solvent and the heated slurry is charged into a drum wherein the pressure is so regulated as to maintain a portion of the solvent in liquid form. During extraction of the hydrocarbons from the coal, additional solvent is added to agitate the drum mass and keep it up to temperature. Subsequently, the pressure is released to vaporize the solvent and at least a portion of the hydrocarbons extracted. The temperature of the mass in the drum is then raised under conditions required to crack the hydrocarbons in the drum and to produce, after subsequent stripping, a solid coke residue. The hydrocarbon products are removed and fractionated into several cuts, one of which is hydrotreated to form the required hydrogen-donor solvent while other fractions can be hydrotreated or hydrocracked to produce a synthetic crude product. The heaviest fraction can be used to produce ash-free coke especially adapted for hydrogen manufacture. The process can be made self-sufficient in hydrogen and furnishes as a by-product a solid carbonaceous material with a useful heating value.

  16. SAFEGUARDS EXPERIENCE ON THE DUPIC FUEL CYCLE PROCESS

    SciTech Connect

    J. HONG; H. KIM; ET AL

    2001-02-01

    Safeguards have been applied to the R and D process for directly fabricating CANDU fuel with PWR spent fuel material. Safeguards issues to be resolved were identified in the areas such as international cooperation on handling foreign origin nuclear material, technology development of operator's measurement system of the bulk handling process of spent fuel material, and a built-in C/S system for independent verification of material flow. The fuel cycle concept (Direct Use of PWR spent fuel in CANDU, DUPIC) was developed in consideration of reutilization of over-flowing spent fuel resources at PWR sites and a reduction of generated high level wastes. All those safeguards issues have been finally resolved, and the first batch of PWR spent fuel material was successfully introduced in the DUPIC lab facility and has been in use for routine process development.

  17. Gaseous Fuel Injection Modeling using a Gaseous Sphere Injection Methodology

    SciTech Connect

    Hessel, R P; Aceves, S M; Flowers, D L

    2006-03-06

    The growing interest in gaseous fuels (hydrogen and natural gas) for internal combustion engines calls for the development of computer models for simulation of gaseous fuel injection, air entrainment and the ensuing combustion. This paper introduces a new method for modeling the injection and air entrainment processes for gaseous fuels. The model uses a gaseous sphere injection methodology, similar to liquid droplet in injection techniques used for liquid fuel injection. In this paper, the model concept is introduced and model results are compared with correctly- and under-expanded experimental data.

  18. Fuel Cell Stations Automate Processes, Catalyst Testing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Glenn Research Center looks for ways to improve fuel cells, which are an important source of power for space missions, as well as the equipment used to test fuel cells. With Small Business Innovation Research (SBIR) awards from Glenn, Lynntech Inc., of College Station, Texas, addressed a major limitation of fuel cell testing equipment. Five years later, the company obtained a patent and provided the equipment to the commercial world. Now offered through TesSol Inc., of Battle Ground, Washington, the technology is used for fuel cell work, catalyst testing, sensor testing, gas blending, and other applications. It can be found at universities, national laboratories, and businesses around the world.

  19. Photodynamic Processes and Lasing in Ce,Yb:LiYXLu1-XF4 Crystals

    NASA Astrophysics Data System (ADS)

    Nurtdinova, L. A.

    2015-09-01

    Measurements of photoconductivity were conducted in LiYXLu1-XF4:RE (RE = Ce(1%), Yb (1%); x = 0..1) crystals. It was found that the excited state absorption transitions of Ce3+ ions are intracenter and terminate at 6s state of cerium ions. Lasing at room temperature was achieved, differential gain (up to ~22%) and tuning range were determined. By lowering the temperature of the active element and using additional antisolarant pumping at 532 nm lasing differential gain efficiency was increased (up to ~ 35%), and the tuning range was expanded.

  20. Renewable hydrogen production for fossil fuel processing

    SciTech Connect

    Greenbaum, E.; Lee, J.W.; Tevault, C.V.

    1995-06-01

    In the fundamental biological process of photosynthesis, atmospheric carbon dioxide is reduced to carbohydrate using water as the source of electrons with simultaneous evolution of molecular oxygen: H{sub 2}O + CO{sub 2} + light {yields} O{sub 2} + (CH{sub 2}O). It is well established that two light reactions, Photosystems I and II (PSI and PSII) working in series, are required to perform oxygenic photosynthesis. Experimental data supporting the two-light reaction model are based on the quantum requirement for complete photosynthesis, spectroscopy, and direct biochemical analysis. Some algae also have the capability to evolve molecular hydrogen in a reaction energized by the light reactions of photosynthesis. This process, now known as biophotolysis, can use water as the electron donor and lead to simultaneous evolution of molecular hydrogen and oxygen. In green algae, hydrogen evolution requires prior incubation under anaerobic conditions. Atmospheric oxygen inhibits hydrogen evolution and also represses the synthesis of hydrogenase enzyme. CO{sub 2} fixation competes with proton reduction for electrons relased from the photosystems. Interest in biophotolysis arises from both the questions that it raises concerning photosynthesis and its potential practical application as a process for converting solar energy to a non-carbon-based fuel. Prior data supported the requirement for both Photosystem I and Photosystem II in spanning the energy gap necessary for biophotolysis of water to oxygen and hydrogen. In this paper we report the at PSII alone is capable of driving sustained simultaneous photoevolution of molecular hydrogen and oxygen in an anaerobically adapted PSI-deficient strain of Chlamydomonas reinhardtii, mutant B4, and that CO{sub 2} competes as an electron acceptor.

  1. Speech Entrainment Compensates for Broca's Area Damage

    PubMed Central

    Fridriksson, Julius; Basilakos, Alexandra; Hickok, Gregory; Bonilha, Leonardo; Rorden, Chris

    2015-01-01

    Speech entrainment (SE), the online mimicking of an audiovisual speech model, has been shown to increase speech fluency in patients with Broca's aphasia. However, not all individuals with aphasia benefit from SE. The purpose of this study was to identify patterns of cortical damage that predict a positive response SE's fluency-inducing effects. Forty-four chronic patients with left hemisphere stroke (15 female) were included in this study. Participants completed two tasks: 1) spontaneous speech production, and 2) audiovisual SE. Number of different words per minute was calculated as a speech output measure for each task, with the difference between SE and spontaneous speech conditions yielding a measure of fluency improvement. Voxel-wise lesion-symptom mapping (VLSM) was used to relate the number of different words per minute for spontaneous speech, SE, and SE-related improvement to patterns of brain damage in order to predict lesion locations associated with the fluency-inducing response to speech entrainment. Individuals with Broca's aphasia demonstrated a significant increase in different words per minute during speech entrainment versus spontaneous speech. A similar pattern of improvement was not seen in patients with other types of aphasia. VLSM analysis revealed damage to the inferior frontal gyrus predicted this response. Results suggest that SE exerts its fluency-inducing effects by providing a surrogate target for speech production via internal monitoring processes. Clinically, these results add further support for the use of speech entrainment to improve speech production and may help select patients for speech entrainment treatment. PMID:25989443

  2. Solid oxide fuel cell process and apparatus

    DOEpatents

    Cooper, Matthew Ellis; Bayless, David J.; Trembly, Jason P.

    2011-11-15

    Conveying gas containing sulfur through a sulfur tolerant planar solid oxide fuel cell (PSOFC) stack for sulfur scrubbing, followed by conveying the gas through a non-sulfur tolerant PSOFC stack. The sulfur tolerant PSOFC stack utilizes anode materials, such as LSV, that selectively convert H.sub.2S present in the fuel stream to other non-poisoning sulfur compounds. The remaining balance of gases remaining in the completely or near H.sub.2S-free exhaust fuel stream is then used as the fuel for the conventional PSOFC stack that is downstream of the sulfur-tolerant PSOFC. A broad range of fuels such as gasified coal, natural gas and reformed hydrocarbons are used to produce electricity.

  3. Reactivity of atomically dispersed Pt(2+) species towards H2: model Pt-CeO2 fuel cell catalyst.

    PubMed

    Lykhach, Yaroslava; Figueroba, Alberto; Camellone, Matteo Farnesi; Neitzel, Armin; Skála, Tomáš; Negreiros, Fabio R; Vorokhta, Mykhailo; Tsud, Nataliya; Prince, Kevin C; Fabris, Stefano; Neyman, Konstantin M; Matolín, Vladimír; Libuda, Jörg

    2016-03-01

    The reactivity of atomically dispersed Pt(2+) species on the surface of nanostructured CeO2 films and the mechanism of H2 activation on these sites have been investigated by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy in combination with density functional calculations. Isolated Pt(2+) sites are found to be inactive towards H2 dissociation due to high activation energy required for H-H bond scission. Trace amounts of metallic Pt are necessary to initiate H2 dissociation on Pt-CeO2 films. H2 dissociation triggers the reduction of Ce(4+) cations which, in turn, is coupled with the reduction of Pt(2+) species. The mechanism of Pt(2+) reduction involves reverse oxygen spillover and formation of oxygen vacancies on Pt-CeO2 films. Our calculations suggest the existence of a threshold concentration of oxygen vacancies associated with the onset of Pt(2+) reduction. PMID:26908194

  4. Electrochemical performance of a solid oxide fuel cell with an anode based on Cu-Ni/CeO2 for methane direct oxidation

    NASA Astrophysics Data System (ADS)

    Hornés, Aitor; Escudero, María J.; Daza, Loreto; Martínez-Arias, Arturo

    2014-03-01

    A CuNi-CeO2/YSZ/LSF solid oxide fuel cell has been fabricated and tested with respect to its electrochemical activity for direct oxidation of dry methane. The electrodes have been prepared by impregnation of corresponding porous YSZ layers, using reverse microemulsions as impregnating medium for the anode (constituted by Cu-Ni at 1:1 atomic ratio in combination with CeO2). On the basis of I-V electrochemical testing complemented by impedance spectroscopy (IS) measurements it is shown the ability of the SOFC for direct oxidation of methane in a rather stable way. Differences in the behavior as a function of operating temperature (1023-1073 K) are also revealed and examined on the basis of analysis of IS spectra.

  5. Energy efficiency enhancement of ethanol electrooxidation on Pd-CeO(2)/C in passive and active polymer electrolyte-membrane fuel cells.

    PubMed

    Bambagioni, Valentina; Bianchini, Claudio; Chen, Yanxin; Filippi, Jonathan; Fornasiero, Paolo; Innocenti, Massimo; Lavacchi, Alessandro; Marchionni, Andrea; Oberhauser, Werner; Vizza, Francesco

    2012-07-01

    Pd nanoparticles have been generated by performing an electroless procedure on a mixed ceria (CeO(2))/carbon black (Vulcan XC-72) support. The resulting material, Pd-CeO(2)/C, has been characterized by means of transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and X-ray diffraction (XRD) techniques. Electrodes coated with Pd-CeO(2)/C have been scrutinized for the oxidation of ethanol in alkaline media in half cells as well as in passive and active direct ethanol fuel cells (DEFCs). Membrane electrode assemblies have been fabricated using Pd-CeO(2)/C anodes, proprietary Fe-Co cathodes, and Tokuyama anion-exchange membranes. The monoplanar passive and active DEFCs have been fed with aqueous solutions of 10 wt% ethanol and 2 M KOH, supplying power densities as high as 66 mW cm(-2) at 25 °C and 140 mW cm(-2) at 80 °C. A comparison with a standard anode electrocatalyst containing Pd nanoparticles (Pd/C) has shown that, at even metal loading and experimental conditions, the energy released by the cells with the Pd-CeO(2)/C electrocatalyst is twice as much as that supplied by the cells with the Pd/C electrocatalyst. A cyclic voltammetry study has shown that the co-support ceria contributes to the remarkable decrease of the onset oxidation potential of ethanol. It is proposed that ceria promotes the formation at low potentials of species adsorbed on Pd, Pd(I)-OH(ads), that are responsible for ethanol oxidation. PMID:22517591

  6. Electrocatalytic and fuel processing studies for portable fuel cells

    NASA Astrophysics Data System (ADS)

    Matter, Paul H.

    In the field of catalysis, the development of alternative catalysts for the oxygen reduction reaction (ORR) in Polymer Electrolyte Membrane Fuel Cell (PEMFC) cathodes has been an ongoing task for researchers over the past two decades. PEM fuel cells are considered to be potential replacements for internal combustion engines in automobiles, and their reduced emissions and better efficiency would have huge payoffs for our environment, and in reducing our nation's dependence on foreign oil. To date, PEMFC cathode over-potentials are still significant, and the only materials discovered to be highly active and stable catalysts in an acidic environment are platinum-based. Despite several major advances in recent years in reducing platinum loading in fuel cell electrodes, the high expense and low availability of platinum will hinder the large-scale commercialization of PEM fuel cells. The most hopeful advances being made in replacing platinum are related to pyrolyzed organic macrocycles with transition metal centers (such as Fe or Co porphyrins and phthalocyanines). Encouragingly, it has recently been discovered that active electrodes could be prepared by heat-treating metal and nitrogen precursors (not necessarily organic macrocycles) together in the presence of a carbon support. In the first study of this dissertation, catalysts for the Oxygen Reduction Reaction (ORR) were prepared by the pyrolysis of acetonitrile over various supports. The supports used included Vulcan Carbon, high purity alumina, silica, magnesia, and these same supports impregnated with Fe, Co, or Ni in the form of acetate salt. The catalysts were characterized by BET surface area analysis, BJH Pore Size Distribution (PSD), conductivity testing, Transmission Electron Microscopy (TEM), Temperature Programmed Oxidation (TPO), Thermo-Gravimetric Analysis (TGA), X-Ray Diffraction (XRD), X-ray Photo-electron Spectroscopy (XPS), Mossbauer Spectroscopy, Rotating Disk Electrode (RDE) half cell testing, and

  7. 77 FR 823 - Guidance for Fuel Cycle Facility Change Processes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... Information DG-3037 was published in the Federal Register on July 14, 2011 (76 FR 41527). The public comment... COMMISSION Guidance for Fuel Cycle Facility Change Processes AGENCY: Nuclear Regulatory Commission. ACTION... issuing a new regulatory guide (RG) 3.74, ``Guidance for Fuel Cycle Facility Change Processes.''...

  8. Automated small scale oil seed processing plant for production of fuel for diesel engines

    SciTech Connect

    Thompson, J.C.; Peterson, C.L.

    1982-01-01

    University of Idaho seed processing research is centered about a CeCoCo oil expeller. A seed preheater-auger, seed bin, meal auger, and oil pump have been constructed to complete the system, which is automated and instrumented. The press, preheater, cake removal auger, and oil transfer pump are tied into a central panel where energy use is measured and the process controlled. Extracted oil weight, meal weight, process temperature, and input energy are all recorded during operation. The oil is transferred to tanks where it settles for 48 hours or more. It is then pumped through a filtering system and stored ready to be used as an engine fuel. The plant has processed over 11,000 kg of seed with an average extraction efficiency of 78 percent. 5 tables.

  9. Long-term evaluation of solid oxide fuel cell candidate materials in a 3-cell generic stack test fixture, part III: Stability and microstructure of Ce-(Mn,Co)-spinel coating, AISI441 interconnect, alumina coating, cathode and anode

    NASA Astrophysics Data System (ADS)

    Chou, Yeong-Shyung; Stevenson, Jeffry W.; Choi, Jung-Pyung

    2014-07-01

    A generic solid oxide fuel cell stack test fixture was developed to evaluate candidate materials and processing under realistic conditions. Part III of the work investigated the stability of Ce-(Mn,Co) spinel coating, AISI441 metallic interconnect, alumina coating, and cell's degradation. After 6000 h test, the spinel coating showed densification with some diffusion of Cr. At the metal interface, segregation of Si and Ti was observed, however, no continuous layer formed. The alumina coating for perimeter sealing areas appeared more dense and thick at the air side than the fuel side. Both the spinel and alumina coatings remained bonded. EDS analysis of Cr within the metal showed small decrease in concentration near the coating interface and would expect to cause no issue of Cr depletion. Inter-diffusion of Ni, Fe, and Cr between spot-welded Ni wire and AISI441 interconnect was observed and Cr-oxide scale formed along the circumference of the weld. The microstructure of the anode and cathode was discussed relating to degradation of the top and middle cells. Overall, the Ce-(Mn,Co) spinel coating, alumina coating, and AISI441 steel showed the desired long-term stability and the developed generic stack fixture proved to be a useful tool to validate candidate materials for SOFC.

  10. Cortical entrainment to music and its modulation by expertise

    PubMed Central

    Doelling, Keith B.; Poeppel, David

    2015-01-01

    Recent studies establish that cortical oscillations track naturalistic speech in a remarkably faithful way. Here, we test whether such neural activity, particularly low-frequency (<8 Hz; delta–theta) oscillations, similarly entrain to music and whether experience modifies such a cortical phenomenon. Music of varying tempi was used to test entrainment at different rates. In three magnetoencephalography experiments, we recorded from nonmusicians, as well as musicians with varying years of experience. Recordings from nonmusicians demonstrate cortical entrainment that tracks musical stimuli over a typical range of tempi, but not at tempi below 1 note per second. Importantly, the observed entrainment correlates with performance on a concurrent pitch-related behavioral task. In contrast, the data from musicians show that entrainment is enhanced by years of musical training, at all presented tempi. This suggests a bidirectional relationship between behavior and cortical entrainment, a phenomenon that has not previously been reported. Additional analyses focus on responses in the beta range (∼15–30 Hz)—often linked to delta activity in the context of temporal predictions. Our findings provide evidence that the role of beta in temporal predictions scales to the complex hierarchical rhythms in natural music and enhances processing of musical content. This study builds on important findings on brainstem plasticity and represents a compelling demonstration that cortical neural entrainment is tightly coupled to both musical training and task performance, further supporting a role for cortical oscillatory activity in music perception and cognition. PMID:26504238

  11. Laboratory Experiments on Convective Entrainment Using a Saline Water Tank

    NASA Astrophysics Data System (ADS)

    Jonker, Harmen J. J.; Jiménez, Maria A.

    2014-06-01

    Entrainment fluxes in a shear-free convective boundary layer have been measured with a saline water tank set-up. The experiments were targeted towards measuring the entrainment behaviour for medium to high Richardson numbers and use a two-layer design, i.e. two stacked non-stratified (neutral) layers with different densities. With laser induced fluorescence (LIF), the entrainment flux of a fluorescent dye is measured for bulk Richardson numbers in the range 30-260. It is proposed that a carefully chosen combination of top-down and bottom-up processes improves the accuracy of LIF-based entrainment observations. The observed entrainment fluxes are about an order of magnitude lower than reported for thermal water tanks: the derived buoyancy entrainment ratio, , is found to be , which is to be compared with for a thermal convection tank (Deardorff et al., J Fluid Mech 100:41-64, 1980). An extensive discussion is devoted to the influence of the Reynolds and Prandtl numbers in laboratory experiments on entrainment.

  12. Cortical entrainment to music and its modulation by expertise.

    PubMed

    Doelling, Keith B; Poeppel, David

    2015-11-10

    Recent studies establish that cortical oscillations track naturalistic speech in a remarkably faithful way. Here, we test whether such neural activity, particularly low-frequency (<8 Hz; delta-theta) oscillations, similarly entrain to music and whether experience modifies such a cortical phenomenon. Music of varying tempi was used to test entrainment at different rates. In three magnetoencephalography experiments, we recorded from nonmusicians, as well as musicians with varying years of experience. Recordings from nonmusicians demonstrate cortical entrainment that tracks musical stimuli over a typical range of tempi, but not at tempi below 1 note per second. Importantly, the observed entrainment correlates with performance on a concurrent pitch-related behavioral task. In contrast, the data from musicians show that entrainment is enhanced by years of musical training, at all presented tempi. This suggests a bidirectional relationship between behavior and cortical entrainment, a phenomenon that has not previously been reported. Additional analyses focus on responses in the beta range (∼15-30 Hz)-often linked to delta activity in the context of temporal predictions. Our findings provide evidence that the role of beta in temporal predictions scales to the complex hierarchical rhythms in natural music and enhances processing of musical content. This study builds on important findings on brainstem plasticity and represents a compelling demonstration that cortical neural entrainment is tightly coupled to both musical training and task performance, further supporting a role for cortical oscillatory activity in music perception and cognition. PMID:26504238

  13. ARTICLE Ionic Conduction and Fuel Cell Performance of Ba0.98Ce0.8Tm0.2O3-α Ceramic

    NASA Astrophysics Data System (ADS)

    Qiu, Li-gan; Wang, Mao-yuan

    2010-12-01

    The perovskite-type oxide solid solution Ba0.98Ce0.8Tm0.2O3-α was prepared by high temperature solid-state reaction and its single phase character was confirmed by X-ray diffraction. The conduction property of the sample was investigated by alternating current impedance spectroscopy and gas concentration cell methods under different gases atmospheres in the temperature range of 500-900°C. The performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured. In wet hydrogen, the sample is a pure protonic conductor with the protonic transport number of 1 in the range of 500-600 °C, a mixed conductor of proton and electron with the protonic transport number of 0.945-0.933 above 600 °C. In wet air, the sample is a mixed conductor of proton, oxide ion, and electronic hole. The protonic transport numbers are 0.010-0.021, and the oxide ionic transport numbers are 0.471-0.382. In hydrogen-air fuel cell, the sample is a mixed conductor of proton, oxide ion and electron, the ionic transport numbers are 0.942-0.885. The fuel cell using Ba0.98Ce0.8Tm0.2O3-α as solid electrolyte can work stably. At 900 °C, the maximum power output density is 110.2 mW/cm2, which is higher than that of our previous cell using BaxCe0.8RE0.2O3-α (x<=1, RE=Y, Eu, Ho) as solid electrolyte.

  14. Reduction of Pt2+ species in model Pt-CeO2 fuel cell catalysts upon reaction with methanol

    NASA Astrophysics Data System (ADS)

    Neitzel, Armin; Johánek, Viktor; Lykhach, Yaroslava; Skála, Tomáš; Tsud, Nataliya; Vorokhta, Mykhailo; Matolín, Vladimír; Libuda, Jörg

    2016-11-01

    The stability of atomically dispersed Pt2+ species on the surface of nanostructured CeO2 films during the reaction with methanol has been investigated by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy. The isolated Pt2+ species were prepared at low Pt concentration in Pt-CeO2 film. Additionally, Pt2+ species coexisting with metallic Pt particles were prepared at high Pt concentration. We found that adsorption of methanol yields similar decomposition products regardless of Pt concentration in Pt-CeO2 films. A small number of oxygen vacancies formed during the methanol decomposition can be replenished in the Pt-CeO2 film with low Pt concentration by diffusion of oxygen from the bulk. In the presence of supported Pt particles, a higher number of oxygen vacancies leads to a partial reduction of the Pt2+ species. The isolated Pt2+ species are reduced under rather strongly reducing conditions only, i.e. during annealing under continuous exposure to methanol. Reduction of isolated Pt2+ species results in the formation of ultra-small Pt particles containing around 25 atoms per particle or less. Such ultra-small Pt particles demonstrate excellent stability against sintering during annealing of Pt-CeO2 film with low Pt concentration under reducing conditions.

  15. Fuel quality/processing study. Volume 4: On site processing studies

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.; Cutrone, M.; Doering, H.; Hickey, J.

    1981-01-01

    Fuel treated at the turbine and the turbine exhaust gas processed at the turbine site are studied. Fuel treatments protect the turbine from contaminants or impurities either in the upgrading fuel as produced or picked up by the fuel during normal transportation. Exhaust gas treatments provide for the reduction of NOx and SOx to environmentally acceptable levels. The impact of fuel quality upon turbine maintenance and deterioration is considered. On site costs include not only the fuel treatment costs as such, but also incremental costs incurred by the turbine operator if a turbine fuel of low quality is not acceptably upgraded.

  16. Analysis of the electrochemical performance of MoNi-CeO2 cermet as anode material for solid oxide fuel cell. Part I. H2, CH4 and H2/CH4 mixtures as fuels

    NASA Astrophysics Data System (ADS)

    Escudero, M. J.; Gómez de Parada, I.; Fuerte, A.; Serrano, J. L.

    2014-05-01

    This paper investigates the catalytic activity and the electrochemical performance of bimetallic formulation combining Mo and Ni with CeO2 (MoNi-Ce) in relation its potential use as anode material for SOFC. The catalytic properties were evaluated for methane partial oxidation as function of temperature and the carbon deposition on the anode surface was analysed by TG-MS. A conversion of 12.8% was reached for partial methane oxidation at 850 °C as well as a high coke resistance. The electrochemical performance was studied in a single cell with La0.58Sr0.4Fe0.8Co0.2O3-δ (LSCF) as cathode, La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) as electrolyte and MoNi-Ce as anode. A thin buffer layer of La0.4Ce0.6O4-δ (LCD) between anode and electrolyte was used to avoid possible interfacial reactions. The cell was tested in different humidified fuels (H2, CH4 and H2/CH4 mixtures) and static air at 750, 800 and 850 °C. The electrochemical behaviour was evaluated by current-voltage curves, impedance spectroscopy and load demand. Stability tests were also performed in pure CH4 at each studied temperature in order to assess degradation of the electrochemical cell performance. No significant performance degradation was detected in all studied fuels even pure methane, which suggests that MoNi-Ce is a suitable anode material for direct methane SOFC.

  17. Measurement of air entrainment in plasma jets

    SciTech Connect

    Fincke, J.R.; Rodriquez, R.; Pentecost, C.G.

    1990-01-01

    The concentration and temperature of air entrained into argon and helium plasma jets has been measured using coherent anti-Stokes Raman spectroscopy (CARS). The argon plasma flow field is characterized by a short region of well behaved laminar flow near the nozzle exit followed by an abrupt transition to turbulence. Once the transition of turbulence occurs, air is rapidly mixed into the jet core. The location of the transition region is determined by the rapid cooling of the jet and the resulting increase in Reynolds number. In contrast, the helium plasma flow field never exceeds a Reynolds number of 200 and remains laminar. The entrainment process in this case is controlled by molecular diffusion rather than turbulent mixing. 9 refs., 5 figs., 1 tab.

  18. Measurement of air entrainment in plasma jets

    NASA Astrophysics Data System (ADS)

    Fincke, J. R.; Rodriquez, R.; Pentecost, C. G.

    The concentration and temperature of air entrained into argon and helium plasma jets has been measured using coherent anti-Stokes Raman spectroscopy (CARS). The argon plasma flow field is characterized by a short region of well behaved laminar flow near the nozzle exit followed by an abrupt transition to turbulence. Once the transition of turbulence occurs, air is rapidly mixed into the jet core. The location of the transition region is determined by the rapid cooling of the jet and the resulting increase in Reynolds number. In contrast, the helium plasma flow field never exceeds a Reynolds number of 200 and remains laminar. The entrainment process in this case is controlled by molecular diffusion rather than turbulent mixing.

  19. Production of synthetic fuels using syngas from a steam hydrogasification and reforming process

    NASA Astrophysics Data System (ADS)

    Raju, Arun Satheesh Kumar

    from carbonaceous feedstocks. Experimental work on the Fischer-Tropsch synthesis has also been performed. A life cycle analysis has been performed with the objective of comparing the life cycle energy consumption and emissions of synthetic diesel fuel produced through the CE-CERT process with other fuel/vehicle combinations. The experimental and simulation results presented here demonstrate that the CE-CERT process is versatile and can potentially handle a number of different feedstocks. CE-CERT process appears to be suitable for commercialization in very large scales with a coal feedstock and also in a distributed network of smaller scale reactors utilizing localized renewable feedstocks.

  20. Fuel quality-processing study. Volume 2: Literature survey

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.; Amero, R.; Murthy, B.; Cutrone, M.

    1981-01-01

    The validity of initial assumptions about raw materials choices and relevant upgrading processing options was confirmed. The literature survey also served to define the on-site (at the turbine location) options for fuel treatment and exhaust gas treatment. The literature survey also contains a substantial compilation of specification and physical property information about liquid fuel products relevant to industrial gas turbines.

  1. A FIRE-ACE/SHEBA Case Study of Mixed-Phase Arctic Boundary Layer Clouds: Entrainment Rate Limitations on Rapid Primary Ice Nucleation Processes

    NASA Technical Reports Server (NTRS)

    Fridlin, Ann; vanDiedenhoven, Bastiaan; Ackerman, Andrew S.; Avramov, Alexander; Mrowiec, Agnieszka; Morrison, Hugh; Zuidema, Paquita; Shupe, Matthew D.

    2012-01-01

    Observations of long-lived mixed-phase Arctic boundary layer clouds on 7 May 1998 during the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE)Arctic Cloud Experiment (ACE)Surface Heat Budget of the Arctic Ocean (SHEBA) campaign provide a unique opportunity to test understanding of cloud ice formation. Under the microphysically simple conditions observed (apparently negligible ice aggregation, sublimation, and multiplication), the only expected source of new ice crystals is activation of heterogeneous ice nuclei (IN) and the only sink is sedimentation. Large-eddy simulations with size-resolved microphysics are initialized with IN number concentration N(sub IN) measured above cloud top, but details of IN activation behavior are unknown. If activated rapidly (in deposition, condensation, or immersion modes), as commonly assumed, IN are depleted from the well-mixed boundary layer within minutes. Quasi-equilibrium ice number concentration N(sub i) is then limited to a small fraction of overlying N(sub IN) that is determined by the cloud-top entrainment rate w(sub e) divided by the number-weighted ice fall speed at the surface v(sub f). Because w(sub c)< 1 cm/s and v(sub f)> 10 cm/s, N(sub i)/N(sub IN)<< 1. Such conditions may be common for this cloud type, which has implications for modeling IN diagnostically, interpreting measurements, and quantifying sensitivity to increasing N(sub IN) (when w(sub e)/v(sub f)< 1, entrainment rate limitations serve to buffer cloud system response). To reproduce observed ice crystal size distributions and cloud radar reflectivities with rapidly consumed IN in this case, the measured above-cloud N(sub IN) must be multiplied by approximately 30. However, results are sensitive to assumed ice crystal properties not constrained by measurements. In addition, simulations do not reproduce the pronounced mesoscale heterogeneity in radar reflectivity that is observed.

  2. Treatment of oxide spent fuel using the lithium reduction process

    SciTech Connect

    Karell, E.J.; Pierce, R.D.; Mulcahey, T.P.

    1996-05-01

    The wide variety in the composition of DOE spent nuclear fuel complicates its long-term disposition because of the potential requirement to individually qualify each type of fuel for repository disposal. Argonne National Laboratory (ANL) has developed the electrometallurgical treatment technique to convert all of these spent fuel types into a single set of disposal forms, simplifying the qualification process. While metallic fuels can be directly processed using the electrometallurgical treatment technique, oxide fuels must first be reduced to the metallic form. The lithium reduction process accomplishes this pretreatment. In the lithium process the oxide components of the fuel are reduced using lithium at 650 C in the presence of molten LiCl, yielding the corresponding metals and Li{sub 2}O. The reduced metal components are then separated from the LiCl salt phase and become the feed material for electrometallurgical treatment. A demonstration test of the lithium reduction process was successfully conducted using a 10-kg batch of simulated oxide spent fuel and engineering-scale equipment specifically constructed for that purpose. This paper describes the lithium process, the equipment used in the demonstration test, and the results of the demonstration test.

  3. Entrainment and detrainment in a simple cumulus cloud model

    NASA Technical Reports Server (NTRS)

    Randall, D. A.; Huffman, G. J.

    1982-01-01

    A cumulus cloud model, analogous to the mixed-layer models of the planetary boundary layer and the upper ocean, is developed using a single, unitary entrainment process in which the motion of the cloud boundary relative to the mean flow is permitted, produced, and controlled by turbulent processes. An alternate theory to the mixing-length theory of Asai and Kasahara (1967) is proposed which completely removes the strong scale-dependence of the Asai-Kasahara model. The model reintroduces scale-dependence by introducing including the pe5turbation pressure term of the equation of vertical motion. It is shown that the model predicts deeper clouds than the Asai-Kasahara model for a given sounding, due to the entrainment assumption and the effects of the perturbation pressure. Lateral entrainment dominates cloud-top entrainment, although finite-difference errors increase the cloud-top entrainment rate from zero to a positive value in actual situations. The fractional entrainment rate for updrafts is determined to vary only slightly with height and to decrease only slowly as the cloud radius increases, while the fractional detrainment rate for updrafts increases with height.

  4. Differential Entrainment of Neuroelectric Delta Oscillations in Developmental Dyslexia

    PubMed Central

    Soltész, Fruzsina; Szűcs, Denes; Leong, Victoria; White, Sonia; Goswami, Usha

    2013-01-01

    Oscillatory entrainment to the speech signal is important for language processing, but has not yet been studied in developmental disorders of language. Developmental dyslexia, a difficulty in acquiring efficient reading skills linked to difficulties with phonology (the sound structure of language), has been associated with behavioural entrainment deficits. It has been proposed that the phonological ‘deficit’ that characterises dyslexia across languages is related to impaired auditory entrainment to speech at lower frequencies via neuroelectric oscillations (<10 Hz, ‘temporal sampling theory’). Impaired entrainment to temporal modulations at lower frequencies would affect the recovery of the prosodic and syllabic structure of speech. Here we investigated event-related oscillatory EEG activity and contingent negative variation (CNV) to auditory rhythmic tone streams delivered at frequencies within the delta band (2 Hz, 1.5 Hz), relevant to sampling stressed syllables in speech. Given prior behavioural entrainment findings at these rates, we predicted functionally atypical entrainment of delta oscillations in dyslexia. Participants performed a rhythmic expectancy task, detecting occasional white noise targets interspersed with tones occurring regularly at rates of 2 Hz or 1.5 Hz. Both groups showed significant entrainment of delta oscillations to the rhythmic stimulus stream, however the strength of inter-trial delta phase coherence (ITC, ‘phase locking’) and the CNV were both significantly weaker in dyslexics, suggestive of weaker entrainment and less preparatory brain activity. Both ITC strength and CNV amplitude were significantly related to individual differences in language processing and reading. Additionally, the instantaneous phase of prestimulus delta oscillation predicted behavioural responding (response time) for control participants only. PMID:24204644

  5. New insight into the promoting role of process on the CeO₂-WO₃/TiO₂ catalyst for NO reduction with NH₃ at low-temperature.

    PubMed

    Zhang, Shule; Zhong, Qin; Shen, Yuge; Zhu, Li; Ding, Jie

    2015-06-15

    This study aimed at investigating the reason of high catalytic activity for CeO2-WO3/TiO2 catalyst from the aspects of WO3 interaction with other species and the NO oxidation process. Analysis by X-ray diffractometry, photoluminescence spectra, diffuse reflectance UV-visible, X-ray photoelectron spectroscopy, density functional theory calculations, electron paramagnetic resonance spectroscopy, temperature-programmed-desorption of NO and in situ diffuse reflectance infrared transform spectroscopy showed that WO3 could interact with CeO2 to improve the electron gaining capability of CeO2 species. In addition, WO3 species acted as electron donating groups to transfer the electrons to CeO2 species. The two aspects enhanced the formation of reduced CeO2 species to improve the formation of superoxide ions. Furthermore, the Ce species were the active sites for the NO adsorption and the superoxide ions over the catalyst needed oxidizing the adsorbed NO to improve the NO oxidation. This process was responsible for the high catalytic activity of CeO2-WO3/TiO2 catalyst. PMID:25746195

  6. Fluid Dynamics of Pressurized, Entrained Coal Gasifiers

    SciTech Connect

    1997-12-31

    Pressurized, entrained gasification is a promising new technology for the clean and efficient combustion of coal. Its principle is to operate a coal gasifier at a high inlet gas velocity to increase the inflow of reactants, and at an elevated pressure to raise the overall efficiency of the process. Unfortunately, because of the extraordinary difficulties involved in performing measurements in hot, pressurized, high-velocity pilot plants, its fluid dynamics are largely unknown. Thus the designer cannot predict with certainty crucial phenomena like erosion, heat transfer and solid capture. In this context, we are conducting a study of the fluid dynamics of Pressurized Entrained Coal Gasifiers (PECGs). The idea is to simulate the flows in generic industrial PECGs using dimensional similitude. To this end, we employ a unique entrained gas-solid flow facility with the flexibility to recycle -rather than discard- gases other than air. By matching five dimensionless parameters, suspensions in mixtures of helium, carbon dioxide and sulfur hexafluoride simulate the effects of pressure and scale-up on the fluid dynamics of PECGS. Because it operates under cold, atmospheric conditions, the laboratory facility is ideal for detailed measurements. These activities are conducted with Air Products & Chemicals, Inc., which is a member of a consortium that includes Foster Wheeler and Deutsche Babcock Energie- und Umwelttechnik AG.

  7. Large Eddy Simulation of the fuel transport and mixing process in a scramjet combustor with rearwall-expansion cavity

    NASA Astrophysics Data System (ADS)

    Cai, Zun; Liu, Xiao; Gong, Cheng; Sun, Mingbo; Wang, Zhenguo; Bai, Xue-Song

    2016-09-01

    Large Eddy Simulation (LES) was employed to investigate the fuel/oxidizer mixing process in an ethylene fueled scramjet combustor with a rearwall-expansion cavity. The numerical solver was first validated for an experimental flow, the DLR strut-based scramjet combustor case. Shock wave structures and wall-pressure distribution from the numerical simulations were compared with experimental data and the numerical results were shown in good agreement with the available experimental data. Effects of the injection location on the flow and mixing process were then studied. It was found that with a long injection distance upstream the cavity, the fuel is transported much further into the main flow and a smaller subsonic zone is formed inside the cavity. Conversely, with a short injection distance, the fuel is entrained more into the cavity and a larger subsonic zone is formed inside the cavity, which is favorable for ignition in the cavity. For the rearwall-expansion cavity, it is suggested that the optimized ignition location with a long upstream injection distance should be in the bottom wall in the middle part of the cavity, while the optimized ignition location with a short upstream injection distance should be in the bottom wall in the front side of the cavity. By employing a cavity direct injection on the rear wall, the fuel mass fraction inside the cavity and the local turbulent intensity will both be increased due to this fueling, and it will also enhance the mixing process which will also lead to increased mixing efficiency. For the rearwall-expansion cavity, the combined injection scheme is expected to be an optimized injection scheme.

  8. Material Properties Governing Co-Current Flame Spread: The Effect of Air Entrainment

    NASA Technical Reports Server (NTRS)

    Coutin, Mickael; Rangwala, Ali S.; Torero, Jose L.; Buckley, Steven G.

    2003-01-01

    A study on the effects of lateral air entrainment on an upward spreading flame has been conducted. The fuel is a flat PMMA plate of constant length and thickness but variable width. Video images and surface temperatures have allowed establishing the progression of the pyrolyis front and on the flame stand-off distance. These measurements have been incorporated into a theoretical formulation to establish characteristic mass transfer numbers ("B" numbers). The mass transfer number is deemed as a material related parameter that could be used to assess the potential of a material to sustain co-current flame spread. The experimental results show that the theoretical formulation fails to describe heat exchange between the flame and the surface. The discrepancies seem to be associated to lateral air entrainment that lifts the flame off the surface and leads to an over estimation of the local mass transfer number. Particle Image Velocimetry (PIV) measurements are in the process of being acquired. These measurements are intended to provide insight on the effect of air entrainment on the flame stand-off distance. A brief description of the methodology to be followed is presented here.

  9. Air entrainment in hairy surfaces

    NASA Astrophysics Data System (ADS)

    Nasto, Alice; Regli, Marianne; Brun, P.-T.; Alvarado, José; Clanet, Christophe; Hosoi, A. E.

    2016-07-01

    Motivated by diving semiaquatic mammals, we investigate the mechanism of dynamic air entrainment in hairy surfaces submerged in liquid. Hairy surfaces are cast out of polydimethylsiloxane elastomer and plunged into a fluid bath at different velocities. Experimentally, we find that the amount of air entrained is greater than what is expected for smooth surfaces. Theoretically, we show that the hairy surface can be considered as a porous medium and we describe the air entrainment via a competition between the hydrostatic forcing and the viscous resistance in the pores. A phase diagram that includes data from our experiments and biological data from diving semiaquatic mammals is included to place the model system in a biological context and predict the regime for which the animal is protected by a plastron of air.

  10. Electrochemical fluorination for processing of used nuclear fuel

    DOEpatents

    Garcia-Diaz, Brenda L.; Martinez-Rodriguez, Michael J.; Gray, Joshua R.; Olson, Luke C.

    2016-07-05

    A galvanic cell and methods of using the galvanic cell is described for the recovery of uranium from used nuclear fuel according to an electrofluorination process. The galvanic cell requires no input energy and can utilize relatively benign gaseous fluorinating agents. Uranium can be recovered from used nuclear fuel in the form of gaseous uranium compound such as uranium hexafluoride, which can then be converted to metallic uranium or UO.sub.2 and processed according to known methodology to form a useful product, e.g., fuel pellets for use in a commercial energy production system.

  11. Synergize fuel and petrochemical processing plans with catalytic reforming

    SciTech Connect

    1997-03-01

    Depending on the market, refiner`s plans to produce clean fuels and higher value petrochemicals will weigh heavily on the catalytic reformer`s flexibility. It seems that as soon as a timely article related to catalytic reforming operations is published, a new {open_quotes}boutique{close_quotes} gasoline fuel specification is slapped on to existing fuel standards, affecting reformer operations and processing objectives. Just as importantly, the petrochemical market (such as aromatics) that refiners are targeting, can be very fickle. That`s why process engineers have endeavored to maintain an awareness of the flexibility that technology suppliers are building into modern catalytic reformers.

  12. Performance of Ni-Fe/gadolinium-doped CeO{sub2} anode supported tubular solid oxide fuel cells using steam reforming of methane

    SciTech Connect

    Liang, B.; Suzuki, T.; Hamamoto, K.; Yamaguchi, T.; Sumi, H.; Fujishiro, Y.; Ingram, B. J.; Carter, J. D.

    2012-03-15

    Iron nanoparticles (Fe{sub 2}O{sub 3}) were added to NiO/gadolinium-doped CeO{sub 2} (GDC) anode supported solid oxide fuel cell (SOFC) for the direct methane-water fuel operation. The cell was co-sintered at 1400 C, and the anode porosity is 31.8%. The main size corresponding to peak volume is around 1.5 {mu}m. When steam and methane directly fed to the cell, the power density is about 0.57 W cm{sup -2} at 650 C. It is the familiar performance for H{sub 2} operation (4 times of flow rate) with same fuel utilization. Compare with the testing temperature of 600 and 650 C, there is almost no carbon fiber deposition at 700 C with steam/methane (S/C) of 5. At the same time, fuel operation of high value of S/C (=3.3) resulted in fiber-like deposition and degradation of power performance based on loading test results.

  13. Entrainment of Air into Vertical Jets in a Crosswind

    NASA Astrophysics Data System (ADS)

    Roberts, K. K.; Solovitz, S.; Freedland, G.; Camp, E.; Cal, R. B.; Mastin, L. G.

    2015-12-01

    During volcanic eruptions, ash concentration must be determined for aviation safety, but the limiting threshold is difficult to distinguish visually. Computational models are typically used to predict ash concentrations, using inputs such as plume height, eruptive duration, and wind speeds. The models also depend on empirical parameters, such as the entrainment of atmospheric air as a ratio of the air inflow speed and the jet speed. Entrainment of atmospheric air plays a critical role in the behavior of volcanic plumes in the atmosphere, impacting the mass flow rate, buoyancy, and particle concentration of the plume. This process is more complex in a crosswind, leading to greater uncertainty in the model results. To address these issues, a laboratory-scale study has been conducted to improve the entrainment models. Observations of a vertical, unconfined jet are performed using Particle Image Velocimetry, while varying jet density using different compressed gases and Reynolds number. To test the effects of a crosswind on plume entrainment rates, these are then compared with similar jet experiments in a wind tunnel. A series of jet geometries, jet speeds and tunnel speeds are considered. The measured velocities are used to determine the entrainment response, which can be used to determine ash concentration over time as atmospheric air is entrained into the plume. We also quantify the mean and the fluctuations in flow velocity.

  14. Experimental insights on the electron transfer and energy transfer processes between Ce{sup 3+}-Yb{sup 3+} and Ce{sup 3+}-Tb{sup 3+} in borate glass

    SciTech Connect

    Sontakke, Atul D. Katayama, Yumiko; Tanabe, Setsuhisa; Ueda, Jumpei; Dorenbos, Pieter

    2015-03-30

    A facile method to describe the electron transfer and energy transfer processes among lanthanide ions is presented based on the temperature dependent donor luminescence decay kinetics. The electron transfer process in Ce{sup 3+}-Yb{sup 3+} exhibits a steady rise with temperature, whereas the Ce{sup 3+}-Tb{sup 3+} energy transfer remains nearly unaffected. This feature has been investigated using the rate equation modeling and a methodology for the quantitative estimation of interaction parameters is presented. Moreover, the overall consequences of electron transfer and energy transfer process on donor-acceptor luminescence behavior, quantum efficiency, and donor luminescence decay kinetics are discussed in borate glass host. The results in this study propose a straight forward approach to distinguish the electron transfer and energy transfer processes between lanthanide ions in dielectric hosts, which is highly advantageous in view of the recent developments on lanthanide doped materials for spectral conversion, persistent luminescence, and related applications.

  15. Examination of turbulent entrainment-mixing mechanisms using a combined approach

    SciTech Connect

    Lu, C.; Liu, Y.; Niu, S.

    2011-10-01

    Turbulent entrainment-mixing mechanisms are investigated by applying a combined approach to the aircraft measurements of three drizzling and two nondrizzling stratocumulus clouds collected over the U.S. Department of Energy's Atmospheric Radiation Measurement Southern Great Plains site during the March 2000 cloud Intensive Observation Period. Microphysical analysis shows that the inhomogeneous entrainment-mixing process occurs much more frequently than the homogeneous counterpart, and most cases of the inhomogeneous entrainment-mixing process are close to the extreme scenario, having drastically varying cloud droplet concentration but roughly constant volume-mean radius. It is also found that the inhomogeneous entrainment-mixing process can occur both near the cloud top and in the middle level of a cloud, and in both the nondrizzling clouds and nondrizzling legs in the drizzling clouds. A new dimensionless number, the scale number, is introduced as a dynamical measure for different entrainment-mixing processes, with a larger scale number corresponding to a higher degree of homogeneous entrainment mixing. Further empirical analysis shows that the scale number that separates the homogeneous from the inhomogeneous entrainment-mixing process is around 50, and most legs have smaller scale numbers. Thermodynamic analysis shows that sampling average of filament structures finer than the instrumental spatial resolution also contributes to the dominance of inhomogeneous entrainment-mixing mechanism. The combined microphysical-dynamical-thermodynamic analysis sheds new light on developing parameterization of entrainment-mixing processes and their microphysical and radiative effects in large-scale models.

  16. Hydrogen purification for fuel cell using CuO/CeO 2-Al 2O 3 catalyst

    NASA Astrophysics Data System (ADS)

    Maciel, Cristhiane Guimarães; Profeti, Luciene Paula Roberto; Assaf, Elisabete Moreira; Assaf, José Mansur

    CuO/CeO 2, CuO/Al 2O 3 and CuO/CeO 2-Al 2O 3 catalysts, with CuO loading varying from 1 to 5 wt.%, were prepared by the citrate method and applied to the preferential oxidation of carbon monoxide in a reaction medium containing large amounts of hydrogen (PROX-CO). The compounds were characterized ex situ by X-ray diffraction, specific surface area measurements, temperature-programmed reduction and temperature-programmed reduction of oxidized surfaces; XANES-PROX in situ experiments were also carried out to study the copper oxidation state under PROX-CO conditions. These analyses showed that in the reaction medium the Cu 0 is present as dispersed particles. On the ceria, these metallic particles are smaller and more finely dispersed, resulting in a stronger metal-support interaction than in CuO/Al 2O 3 or CuO/CeO 2-Al 2O 3 catalysts, providing higher PROX-CO activity and better selectivity in the conversion of CO to CO 2 despite the greater BET area presented by samples supported on alumina. It is also shown that the lower CuO content, the higher metal dispersion and consequently the catalytic activity. The redox properties of the ceria support also contributed to catalytic performance.

  17. Comprehensive modeling and numerical investigation of entrained-flow coal gasifiers

    NASA Astrophysics Data System (ADS)

    Silaen, Armin Karen

    Numerical simulations of coal gasification process inside a generic 2-stage entrained-flow gasifier are carried out using the commercial CFD solver ANSYS/FLUENT. The 3-D Navier-Stokes equations and eight species transport equations are solved with three heterogeneous global reactions, three homogeneous reactions, and one thermal cracking equation of volatiles. Finite rates are used for the heterogeneous solid-gas reactions. Both finite rate and eddy-breakup combustion models are calculated for each homogeneous gas-gas reaction, and the smaller of the two rates is used. Lagrangian-Eulerian method is employed. The Eulerian method calculates the continuous phase while the Lagrangian method tracks each coal particle. Fundamental study is carried out to investigate effects of five turbulence models (standard k-epsilon, k-o, RSM, k-o SST, and k-epsilon RNG) and four devolatilization models (Kobayashi, single rate, constant rate, and CPD) on gasification simulation. A study is also conducted to investigate the effects of different operation parameters on gasification process including coal mixture (dry vs. slurry), oxidant (oxygen-blown vs. air-blown), and different coal distributions between two stages. Finite-rate model and instantaneous gasification model are compared. It is revealed that the instantaneous gasification approach can provide an overall evaluation of relative changes of gasifier performance in terms of temperature, heating value, and gasification efficiency corresponding to parametric variations, but not adequately capture the local gasification process predicted by the finite rate model in most part of the gasifier. Simulations are performed to help with design modifications of a small industrial demonstration entrained-flow gasifier. It is discovered that the benefit of opening the slag tap on the quench-type gasifier wider by allowing slag to move successfully without clogging is compromised by increased heat losses, reduced gasification performance

  18. Distillate fuel-oil processing for phosphoric acid fuel-cell power plants

    SciTech Connect

    Ushiba, K. K.

    1980-02-01

    The current efforts to develop distillate oil-steam reforming processes are reviewed, and the applicability of these processes for integration with the fuel cell are discussed. The development efforts can be grouped into the following processing approaches: high-temperature steam reforming (HTSR); autothermal reforming (ATR); autothermal gasification (AG); and ultra desulfurization followed by steam reforming. Sulfur in the feed is a key problem in the process development. A majority of the developers consider sulfur as an unavoidable contaminant of distillate fuel and are aiming to cope with it by making the process sulfur-tolerant. In the HTSR development, the calcium aluminate catalyst developed by Toyo Engineering represents the state of the art. United Technology (UTC), Engelhard, and Jet Propulsion Laboratory (JPL) are also involved in the HTSR research. The ATR of distillate fuel is investigated by UTC and JPL. The autothermal gasification (AG) of distillate fuel is being investigated by Engelhard and Siemens AG. As in the ATR, the fuel is catalytically gasified utilizing the heat generated by in situ partial combustion of feed, however, the goal of the AG is to accomplish the initial breakdown of the feed into light gases and not to achieve complete conversion to CO and H/sub 2/. For the fuel-cell integration, a secondary reforming of the light gases from the AG step is required. Engelhard is currently testing a system in which the effluent from the AG section enters the steam-reforming section, all housed in a single vessel. (WHK)

  19. Analysis of the ATR fuel element swaging process

    SciTech Connect

    Richins, W.D.; Miller, G.K.

    1995-12-01

    This report documents a detailed evaluation of the swaging process used to connect fuel plates to side plates in Advanced Test Reactor (ATR) fuel elements. The swaging is a mechanical process that begins with fitting a fuel plate into grooves in the side plates. Once a fuel plate is positioned, a lip on each of two side plate grooves is pressed into the fuel plate using swaging wheels to form the joints. Each connection must have a specified strength (measured in terms, of a pullout force capacity) to assure that these joints do not fail during reactor operation. The purpose of this study is to analyze the swaging process and associated procedural controls, and to provide recommendations to assure that the manufacturing process produces swaged connections that meet the minimum strength requirement. The current fuel element manufacturer, Babcock and Wilcox (B&W) of Lynchburg, Virginia, follows established procedures that include quality inspections and process controls in swaging these connections. The procedures have been approved by Lockheed Martin Idaho Technologies and are designed to assure repeatability of the process and structural integrity of each joint. Prior to July 1994, ATR fuel elements were placed in the Hydraulic Test Facility (HTF) at the Idaho National Engineering Laboratory (AGNAIL), Test Reactor Area (TRA) for application of Boehmite (an aluminum oxide) film and for checking structural integrity before placement of the elements into the ATR. The results presented in this report demonstrate that the pullout strength of the swaged connections is assured by the current manufacturing process (with several recommended enhancements) without the need for- testing each element in the HTF.

  20. Process for separating water and solids from fuels

    SciTech Connect

    Filho, J.H.; Bachmann, D.L.

    1987-11-17

    A process for separating water and solid particles from a fuel oil feedstock is described comprising: subjecting the feedstock to a first separation in a scroll type centrifugal separator to form a first recovered fuel stream and an oil cake; subjecting at least the first recovered fuel stream to a second separation in a centrifugal disc separator to form a clean fuel stream, an oil-bearing water stream and a sludge stream; treating the oil-bearing water stream in a separator to recover the oil; treating the oil cake removed from the first separation with a solvent in order to form a suspension; mixing the suspension with the sludge stream to form a mixture; feeding the mixture to a filter press to yield a solid reject and a filtrate; separating the filtrate into a decantate and recovered oil; mixing at least a portion of the recovered oil with first recovered fuel stream to form a semi-cleaned fuel stream; and subjecting the semi-cleaned fuel stream to the second separation in a centrifugal disc separator to form the clean fuel stream.

  1. A Brief Review of Past INL Work Assessing Radionuclide Content in TMI-2 Melted Fuel Debris: The Use of 144Ce as a Surrogate for Pu Accountancy

    SciTech Connect

    D. L. Chichester; S. J. Thompson

    2013-09-01

    This report serves as a literature review of prior work performed at Idaho National Laboratory, and its predecessor organizations Idaho National Engineering Laboratory (INEL) and Idaho National Engineering and Environmental Laboratory (INEEL), studying radionuclide partitioning within the melted fuel debris of the reactor of the Three Mile Island 2 (TMI-2) nuclear power plant. The purpose of this review is to document prior published work that provides supporting evidence of the utility of using 144Ce as a surrogate for plutonium within melted fuel debris. When the TMI-2 accident occurred no quantitative nondestructive analysis (NDA) techniques existed that could assay plutonium in the unconventional wastes from the reactor. However, unpublished work performed at INL by D. W. Akers in the late 1980s through the 1990s demonstrated that passive gamma-ray spectrometry of 144Ce could potentially be used to develop a semi-quantitative correlation for estimating plutonium content in these materials. The fate and transport of radioisotopes in fuel from different regions of the core, including uranium, fission products, and actinides, appear to be well characterized based on the maximum temperature reached by fuel in different parts of the core and the melting point, boiling point, and volatility of those radioisotopes. Also, the chemical interactions between fuel, fuel cladding, control elements, and core structural components appears to have played a large role in determining when and how fuel relocation occurred in the core; perhaps the most important of these reaction appears to be related to the formation of mixed-material alloys, eutectics, in the fuel cladding. Because of its high melting point, low volatility, and similar chemical behavior to plutonium, the element cerium appears to have behaved similarly to plutonium during the evolution of the TMI-2 accident. Anecdotal evidence extrapolated from open-source literature strengthens this logical feasibility for

  2. Evaluation of gasification and gas cleanup processes for use in molten-carbonate fuel-cell power plants. Task B interim report

    SciTech Connect

    Not Available

    1981-12-01

    This interim report satisfies the Task B requirement for DOE Contract DE-AC21-81MC16220 to define process configurations for systems suitable for supplying fuel to molten carbonate fuel cells (MCFC) in industrial and utility power plants. The information and data necessary for this study were extracted from sources in the public domain, including reports from DOE, EPRI, and EPA; work sponsored in whole or in part by Federal agencies; and from trade journals, MCFC developers, and manufacturers. The configurations include entrained, fluidized-bed, gravitating-bed, and molten salt gasifiers, both air and oxygen blown. Desulfurization systems utilizing wet scrubbing processes, such as Selexol and Rectisol II, and dry sorbents, such as iron oxide and dolomite, were chosen for evaluation.

  3. Timescales of massive human entrainment.

    PubMed

    Fusaroli, Riccardo; Perlman, Marcus; Mislove, Alan; Paxton, Alexandra; Matlock, Teenie; Dale, Rick

    2015-01-01

    The past two decades have seen an upsurge of interest in the collective behaviors of complex systems composed of many agents entrained to each other and to external events. In this paper, we extend the concept of entrainment to the dynamics of human collective attention. We conducted a detailed investigation of the unfolding of human entrainment--as expressed by the content and patterns of hundreds of thousands of messages on Twitter--during the 2012 US presidential debates. By time-locking these data sources, we quantify the impact of the unfolding debate on human attention at three time scales. We show that collective social behavior covaries second-by-second to the interactional dynamics of the debates: A candidate speaking induces rapid increases in mentions of his name on social media and decreases in mentions of the other candidate. Moreover, interruptions by an interlocutor increase the attention received. We also highlight a distinct time scale for the impact of salient content during the debates: Across well-known remarks in each debate, mentions in social media start within 5-10 seconds after it occurs; peak at approximately one minute; and slowly decay in a consistent fashion across well-known events during the debates. Finally, we show that public attention after an initial burst slowly decays through the course of the debates. Thus we demonstrate that large-scale human entrainment may hold across a number of distinct scales, in an exquisitely time-locked fashion. The methods and results pave the way for careful study of the dynamics and mechanisms of large-scale human entrainment. PMID:25880357

  4. Optimum catalytic process for alcohol fuels from syngas

    SciTech Connect

    Not Available

    1990-04-28

    The objectives of this contract are to discover and evaluate the catalytic properties of novel homogeneous, heterogeneous, or combination catalytic systems for the production of alcohol fuel extenders from syngas, to evaluate analytically and on the bench scale novel reactor concepts for use in converting syngas to liquid fuel products, and to develop on the bench scale the best combination of chemistry, reactor, and total process configuration to achieve the minimum product cost for conversion of syngas to liquid fuel products. Methanol production and heterogeneous catalysis utilizing transition elements supported on metal oxides with spinel structure are discussed. 12 figs., 16 tabs.

  5. Process of producing liquid hydrocarbon fuels from biomass

    DOEpatents

    Kuester, James L.

    1987-07-07

    A continuous thermochemical indirect liquefaction process to convert various biomass materials into diesel-type transportation fuels which fuels are compatible with current engine designs and distribution systems comprising feeding said biomass into a circulating solid fluidized bed gasification system to produce a synthesis gas containing olefins, hydrogen and carbon monoxide and thereafter introducing the synthesis gas into a catalytic liquefaction system to convert the synthesis gas into liquid hydrocarbon fuel consisting essentially of C.sub.7 -C.sub.17 paraffinic hydrocarbons having cetane indices of 50+.

  6. Process of producing liquid hydrocarbon fuels from biomass

    DOEpatents

    Kuester, J.L.

    1987-07-07

    A continuous thermochemical indirect liquefaction process is described to convert various biomass materials into diesel-type transportation fuels which fuels are compatible with current engine designs and distribution systems comprising feeding said biomass into a circulating solid fluidized bed gasification system to produce a synthesis gas containing olefins, hydrogen and carbon monoxide and thereafter introducing the synthesis gas into a catalytic liquefaction system to convert the synthesis gas into liquid hydrocarbon fuel consisting essentially of C[sub 7]-C[sub 17] paraffinic hydrocarbons having cetane indices of 50+. 1 fig.

  7. Preferential oxidation of methanol and carbon monoxide for gas cleanup during methanol fuel processing

    SciTech Connect

    Birdsell, S.A.; Vanderborgh, N.E.; Inbody, M.A.

    1993-07-01

    Methanol fuel processing generates hydrogen for low-temperature, PEM fuel cell systems now being considered for transportation and other applications. Although liquid methanol fuel is convenient for this application, existing fuel processing techniques generate contaminants that degrade fuel cell performance. Through mathematical models and laboratory experiments chemical processing is described that removes CO and other contaminants from the anode feed stream.

  8. Irregular Speech Rate Dissociates Auditory Cortical Entrainment, Evoked Responses, and Frontal Alpha

    PubMed Central

    Kayser, Stephanie J.; Ince, Robin A.A.; Gross, Joachim

    2015-01-01

    The entrainment of slow rhythmic auditory cortical activity to the temporal regularities in speech is considered to be a central mechanism underlying auditory perception. Previous work has shown that entrainment is reduced when the quality of the acoustic input is degraded, but has also linked rhythmic activity at similar time scales to the encoding of temporal expectations. To understand these bottom-up and top-down contributions to rhythmic entrainment, we manipulated the temporal predictive structure of speech by parametrically altering the distribution of pauses between syllables or words, thereby rendering the local speech rate irregular while preserving intelligibility and the envelope fluctuations of the acoustic signal. Recording EEG activity in human participants, we found that this manipulation did not alter neural processes reflecting the encoding of individual sound transients, such as evoked potentials. However, the manipulation significantly reduced the fidelity of auditory delta (but not theta) band entrainment to the speech envelope. It also reduced left frontal alpha power and this alpha reduction was predictive of the reduced delta entrainment across participants. Our results show that rhythmic auditory entrainment in delta and theta bands reflect functionally distinct processes. Furthermore, they reveal that delta entrainment is under top-down control and likely reflects prefrontal processes that are sensitive to acoustical regularities rather than the bottom-up encoding of acoustic features. SIGNIFICANCE STATEMENT The entrainment of rhythmic auditory cortical activity to the speech envelope is considered to be critical for hearing. Previous work has proposed divergent views in which entrainment reflects either early evoked responses related to sound encoding or high-level processes related to expectation or cognitive selection. Using a manipulation of speech rate, we dissociated auditory entrainment at different time scales. Specifically, our

  9. A Pd/C-CeO2 Anode Catalyst for High-Performance Platinum-Free Anion Exchange Membrane Fuel Cells.

    PubMed

    Miller, Hamish A; Lavacchi, Alessandro; Vizza, Francesco; Marelli, Marcello; Di Benedetto, Francesco; D'Acapito, Francesco; Paska, Yair; Page, Miles; Dekel, Dario R

    2016-05-10

    One of the biggest obstacles to the dissemination of fuel cells is their cost, a large part of which is due to platinum (Pt) electrocatalysts. Complete removal of Pt is a difficult if not impossible task for proton exchange membrane fuel cells (PEM-FCs). The anion exchange membrane fuel cell (AEM-FC) has long been proposed as a solution as non-Pt metals may be employed. Despite this, few examples of Pt-free AEM-FCs have been demonstrated with modest power output. The main obstacle preventing the realization of a high power density Pt-free AEM-FC is sluggish hydrogen oxidation (HOR) kinetics of the anode catalyst. Here we describe a Pt-free AEM-FC that employs a mixed carbon-CeO2 supported palladium (Pd) anode catalyst that exhibits enhanced kinetics for the HOR. AEM-FC tests run on dry H2 and pure air show peak power densities of more than 500 mW cm(-2) . PMID:27062251

  10. Doing Duo - a case study of entrainment in William Forsythe's choreography "Duo".

    PubMed

    Waterhouse, Elizabeth; Watts, Riley; Bläsing, Bettina E

    2014-01-01

    Entrainment theory focuses on processes in which interacting (i.e., coupled) rhythmic systems stabilize, producing synchronization in the ideal sense, and forms of phase related rhythmic coordination in complex cases. In human action, entrainment involves spatiotemporal and social aspects, characterizing the meaningful activities of music, dance, and communication. How can the phenomenon of human entrainment be meaningfully studied in complex situations such as dance? We present an in-progress case study of entrainment in William Forsythe's choreography Duo, a duet in which coordinated rhythmic activity is achieved without an external musical beat and without touch-based interaction. Using concepts of entrainment from different disciplines as well as insight from Duo performer Riley Watts, we question definitions of entrainment in the context of dance. The functions of chorusing, turn-taking, complementary action, cues, and alignments are discussed and linked to supporting annotated video material. While Duo challenges the definition of entrainment in dance as coordinated response to an external musical or rhythmic signal, it supports the definition of entrainment as coordinated interplay of motion and sound production by active agents (i.e., dancers) in the field. Agreeing that human entrainment should be studied on multiple levels, we suggest that entrainment between the dancers in Duo is elastic in time and propose how to test this hypothesis empirically. We do not claim that our proposed model of elasticity is applicable to all forms of human entrainment nor to all examples of entrainment in dance. Rather, we suggest studying higher order phase correction (the stabilizing tendency of entrainment) as a potential aspect to be incorporated into other models. PMID:25374522

  11. Microwave Processing of Simulated Advanced Nuclear Fuel Pellets

    SciTech Connect

    D.E. Clark; D.C. Folz

    2010-08-29

    Throughout the three-year project funded by the Department of Energy (DOE) and lead by Virginia Tech (VT), project tasks were modified by consensus to fit the changing needs of the DOE with respect to developing new inert matrix fuel processing techniques. The focus throughout the project was on the use of microwave energy to sinter fully stabilized zirconia pellets using microwave energy and to evaluate the effectiveness of techniques that were developed. Additionally, the research team was to propose fundamental concepts as to processing radioactive fuels based on the effectiveness of the microwave process in sintering the simulated matrix material.

  12. Simulating entrainment and particle fluxes in stratified estuaries

    SciTech Connect

    Jensen, A.; Jirka, G.; Lion, L.W.; Brunk, B.

    1999-04-01

    Settling and entrainment are the dominant processes governing noncohesive particle concentration throughout the water column of salt-wedge estuaries. Determination of the relative contribution of these transport processes is complicated by vertical gradients in turbulence and fluid density. A differential-turbulence column (DTC) was designed to simulate a vertical section of a natural water column. With satisfactory characterization of turbulence dissipation and saltwater entrainment, the DTC facilitates controlled studies of suspended particles under estuarine conditions. The vertical decay of turbulence in the DTC was found to obey standard scaling law relations when the characteristic length scale for turbulence in the apparatus was incorporated. The entrainment rate of a density interface also followed established grid-stirred turbulence scaling laws. These relations were used to model the change in concentration of noncohesive particles above a density interface. Model simulations and experimental data from the DTC were consistent over the range of conditions encountered in natural salt-wedge estuaries. Results suggest that when the ratio of entrainment rate to particle settling velocity is small, sedimentation is the dominant transport process, while entrainment becomes significant as the ratio increases.

  13. Process review of lignocellulose biochemical conversion to fuel ethanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review is meant to give a general technical review of the state-of-the-art in process technology for the biochemical conversion of lignocellulose to fuel ethanol. The proceeding details the chemical structure of biomass and basic process steps needed for extracting carbohydrates as sugars and ...

  14. Entrainment by the jet in HH 47

    NASA Technical Reports Server (NTRS)

    Raymond, John C.; Morse, Jon A.; Hartigan, P.; Curiel, S.; Heathcote, Steve

    1994-01-01

    Fabry-Perot images of the HH 47 optical jet show that the velocity decreases from the center toward the edges which is interpreted as evidence for entrainment. Those images can be used to investigate the rate of entrainment required to account for the observed luminosity. Entrainment along the jet can account for only small fractions of the jet mass and the molecular outflow seen in CO. We compare the density, excitation, and velocity structure of the jet with the predictions of viscous entrainment models and models of entrainment by expulsion of jet material by internal shocks, and find that either type of model can explain the general features.

  15. CONVERTING PYROLYSIS OILS TO RENEWABLE TRANSPORT FUELS: PROCESSING CHALLENGES & OPPORTUNITIES

    SciTech Connect

    Holmgren, Jennifer; Nair, Prabhakar N.; Elliott, Douglas C.; Bain, Richard; Marinangelli, Richard

    2008-03-11

    To enable a sustained supply of biomass-based transportation fuels, the capability to process feedstocks outside the food chain must be developed. Significant industry efforts are underway to develop these new technologies, such as converting cellulosic wastes to ethanol. UOP, in partnership with U.S. Government labs, NREL and PNNL, is developing an alternate route using cellulosic feedstocks. The waste biomass is first subjected to a fast pyrolysis operation to generate pyrolysis oil (pyoil for short). Current efforts are focused on developing a thermochemical platform to convert pyoils to renewable gasoline, diesel and jet fuel. The fuels produced will be indistinguishable from their fossil fuel counterparts and, therefore, will be compatible with existing transport and distribution infrastructure.

  16. Processing of carbon composite paper as electrode for fuel cell

    NASA Astrophysics Data System (ADS)

    Mathur, R. B.; Maheshwari, Priyanka H.; Dhami, T. L.; Sharma, R. K.; Sharma, C. P.

    The porous carbon electrode in a fuel cell not only acts as an electrolyte and a catalyst support, but also allows the diffusion of hydrogen fuel through its fine porosity and serves as a current-carrying conductor. A suitable carbon paper electrode is developed and possesses the characteristics of high porosity, permeability and strength along with low electrical resistivity so that it can be effectively used in proton-exchange membrane and phosphoric acid fuel cells. The electrode is prepared through a combination of two important techniques, viz., paper-making technology by first forming a porous chopped carbon fibre preform, and composite technology using a thermosetting resin matrix. The study reveals an interdependence of one parameter on another and how judicious choice of the processing conditions are necessary to achieve the desired characteristics. The current-voltage performance of the electrode in a unit fuel cell matches that of a commercially-available material.

  17. Motor fuel alkylation process utilizing low acid

    SciTech Connect

    Kocal, J.A.; Imai, T.

    1987-01-06

    A process is described for the alkylation of an isoparaffin with an olefin acting agent comprising contacting the isoparaffin with the olefin acting agent at alkylation conditions in the presence of a catalyst. The catalyst consists essentially of an anhydrous, nonalcoholic mixture of from about 5 to 15 wt. % methyl tert-butyl ether and from 85 to 95 wt. % hydrofluoric acid. The volumetric ratio of hydrofluoric acid to isoparaffin and olefin acting agent is less than 0.75.

  18. Entrainment in oscillatory zero-mean flow

    NASA Astrophysics Data System (ADS)

    Medina, P.; Sanchez, M. A.

    2009-04-01

    The dynamical processes associated with the stably stratified atmospheric boundary layer or in the ocean thermocline are less well understood than those of its convective counterparts. This is due to its complexity, and the fact that buoyancy reduces entrainment across density interfaces. We present results on a series of laboratory experiments where a sharp density interface generated by either salt concentration or heat, advances due to grid stirred turbulence. We parametrize the level of buoyancy at the density interface by a local Richardson number defined in terms of the density difference across the interface, which may be due to a temperature or salinity jump. L is the integral lengthscale and u' is the r.m.s. velocity scale. So Ri = C L/u 2. The laboratory experiments were designed to compare the entrainment produced by zero-mean turbulence in heat or salt density interfaces. In the experiment we used a small perspex box of 15 by 10 cm in base, a small mesh grid (M= 0.8 cm ) driven by a motor. So as to generate the density interface by disolving salt in the bottom layer of the water column or by heating the top layer, we added the top light layer, which had a density difference carefully set up by means of a sponge float. The grid was set to oscillate with fixed frequency and stroke at the begining of the experiment and the velocity of advance of the interface Ve was measured by looking at a Shadowgraph or by video recording. The turbulent parameters are derived from previous measurements as a function of the distance between the grid center and the interface z as: l = 0.1 z and the turbulent velocity údecays inversely proportinal to the distance z. There are several mechanisms that produce mixing across the density interface. And there is a dependence of the Prandtl number on the Entrainment law. The entrainment is a power function of the local Richardson number, and the value of the empirical exponent n(Ri,Pr) is compared with previous results. The

  19. Flame Synthesis of Nanosized Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O Catalysts for the Water-Gas Shift (WGS) Reaction

    SciTech Connect

    Pati, R.; Lee, I; Hou, S; Akhuemonkhan, O; Gaskell, K; Wang, Q; Frenkel, A; Chu, D; Salamanca-Riba, L; Ehrman, S

    2009-01-01

    A flame synthesis method has been used to prepare nanosized, high-surface-area Cu-Ce-O, Ni-Ce-O, and Fe-Ce-O catalysts from aqueous solutions of metal acetate precursors. The particles were formed by vaporization of the precursors followed by reaction and then gas to particle conversion. The specific surface areas of the synthesized powders ranged from 127 to 163 m{sup 2}/g. High-resolution transmission electron microscope imaging showed that the particle diameters for the ceria materials are in the range of 3-10 nm, and a thin layer of amorphous material was observed on the surface of the particles. The presence and surface enrichment of the transition-metal oxides (CuO, NiO, and Fe{sub 2}O{sub 3}) on the ceria particles were detected using X-ray photoelectron spectroscopy. Electron energy-loss spectroscopic studies suggest the formation of a core-shell structure in the as-prepared particles. Extended X-ray absorption fine structure studies suggest that the dopants in all M-Ce-O systems are almost isostructural with their oxide counterparts, indicating the doping materials form separate oxide phases (CuO, Fe{sub 2}O{sub 3}, NiO) within the host matrix (CeO{sub 2}). Etching results confirm that most of the transition-metal oxides are present on the surface of CeO{sub 2}, easily dissolved by nitric acid. The performance of the flame-synthesized catalysts was examined toward water-gas shift (WGS) activity for fuel processing applications. The WGS activity of metal ceria catalysts decreases in the order Cu-Ce-O > Ni-Ce-O > Fe-Ce-O > CeO{sub 2} with a feed mixture having a hydrogen to carbon monoxide (H{sub 2}/CO) ratio of 1. There was no methane formation for these catalysts under the tested conditions.

  20. Saturation point representation of cloud-top entrainment instability

    NASA Technical Reports Server (NTRS)

    Boers, Reinout

    1991-01-01

    Cloud-top entrainment instability was investigated using a mixing line analysis. Mixing time scales are closely related to the actual size of the parcel, so that local instabilities are largely dependent on the scales of mixing near the cloud top. Given a fixed transport velocity, variation over a small range of parcel length scales (parcel mixing velocities) turns an energy-producing mixing process into an energy-consuming mixing process. It is suggested that a single criterion for cloud-top entrainment instability will not be found due to the role of at least three factors operating more or less independently; the stability of the mixing line, the entrainment speed, and the strength of the internal boundary-layer circulation.

  1. Pyrolysis process for producing fuel gas

    NASA Technical Reports Server (NTRS)

    Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

    2007-01-01

    Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

  2. Processing waste fats into a fuel oil substitute

    SciTech Connect

    Pudel, F.; Lengenfeld, P.

    1993-12-31

    Waste fats have a high energy potential. They also contain impurities. For example, fats used for deep-frying contain high contents of solids, water, and chlorides. The process described in this paper removes the impurities by simple processing such as screening, washing, separating, drying, and filtering. The final quality of processed fat allows its use as a fuel oil substitute, and also as a raw material for chemical production.

  3. Entrainment in electrohydrodynamic heat pipes

    NASA Technical Reports Server (NTRS)

    Jones, T. B.; Perry, M. P.

    1972-01-01

    A theoretical analysis for predicting the onset of the Kelvin-Helmholtz instability is reported. The model for the analysis is described, and the derived stability criterion are given. It is concluded that surface tension plays a role in the entrainment limit of electro hydrodynamic heat pipes. The surface of the liquid in an EHD flow structure is open, with no restriction placed on the wavenumbers of perturbations.

  4. Timescales of Massive Human Entrainment

    PubMed Central

    Fusaroli, Riccardo; Perlman, Marcus; Mislove, Alan; Paxton, Alexandra; Matlock, Teenie; Dale, Rick

    2015-01-01

    The past two decades have seen an upsurge of interest in the collective behaviors of complex systems composed of many agents entrained to each other and to external events. In this paper, we extend the concept of entrainment to the dynamics of human collective attention. We conducted a detailed investigation of the unfolding of human entrainment—as expressed by the content and patterns of hundreds of thousands of messages on Twitter—during the 2012 US presidential debates. By time-locking these data sources, we quantify the impact of the unfolding debate on human attention at three time scales. We show that collective social behavior covaries second-by-second to the interactional dynamics of the debates: A candidate speaking induces rapid increases in mentions of his name on social media and decreases in mentions of the other candidate. Moreover, interruptions by an interlocutor increase the attention received. We also highlight a distinct time scale for the impact of salient content during the debates: Across well-known remarks in each debate, mentions in social media start within 5–10 seconds after it occurs; peak at approximately one minute; and slowly decay in a consistent fashion across well-known events during the debates. Finally, we show that public attention after an initial burst slowly decays through the course of the debates. Thus we demonstrate that large-scale human entrainment may hold across a number of distinct scales, in an exquisitely time-locked fashion. The methods and results pave the way for careful study of the dynamics and mechanisms of large-scale human entrainment. PMID:25880357

  5. Performance and sulfur poisoning of Ni/CeO2 impregnated La0.75Sr0.25Cr0.5Mn0.5O3-δ anode in solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Yiqian; Zhang, Yaohui; Zhu, Xingbao; Wang, Zhihong; Lü, Zhe; Huang, Xiqiang; Zhou, Yongjun; Zhu, Lin; Jiang, Wei

    2015-07-01

    In this study, comparison experiments are conducted based on yttria-stabilized zirconia (YSZ) electrolyte supported single solid oxide fuel cells (SOFCs) with pure La0.75Sr0.25Cr0.5Mn0.5O3-δ (LSCrM) or Ni/CeO2 impregnated LSCrM anodes. The single cells are tested in dry H2 and H2/H2S (50 ppm) mixture, respectively. Compared with the pure LSCrM anode, the cell with Ni/CeO2 impregnated LSCrM presents a significant performance improvement when the pure H2 is fueled to the anode, and shows a good stability during a constant-current discharge testing (398 mA cm-2). When the fuel is switched to H2/H2S mixture, the cell with Ni/CeO2 impregnated LSCrM anode still shows a remarkable constant-current discharge (120 mA cm-2) performance compared with pure LSCrM anode. The Ni/CeO2 impregnation can improve the electrochemical performance of the LSCrM anode without any sacrifice of sulfur tolerance ability. The Ni/CeO2 impregnated LSCrM might be a potential anode material for solid oxide fuel cell operating in sulfur-containing fuels. The XRD and XPS results demonstrate that the anode poisoning product is composed of adsorbed sulfur, metal sulfides and sulfate radical. The mass spectrum result confirms that the poisoning mechanism involves the reaction of sulfur with anode rather than the direct reaction between H2S gas and anode.

  6. A new family of Ce-doped SmFeO3 perovskite for application in symmetrical solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Fan, Weiwei; Sun, Zhu; Wang, Junkai; Zhou, Jun; Wu, Kai; Cheng, Yonghong

    2016-04-01

    Here, a nanoporous Sm0.95Ce0.05FeO3-δ (SCFO) perovskite-type oxide is assessed in regard to its possible use as an electrode material for symmetrical solid oxide fuel cells. It is found that SCFO has a good redox stability after characterizing the sample which is calcined at 850 °C in 5% H2/N2 for 10 h. Optimized electrochemical performances are obtained in both the nanoporous anode and cathode which are mainly due to the high catalytic activity of SCFO for redox reaction. The peak power density of SCFO|YSZ|SCFO symmetrical cell is as high as 130 mW cm-2 at 800 °C using pure, humidified H2 as the fuel. Moreover, the maximum power density of 193 mW cm-2 can be obtained for the SCFO:YSZ(7:3)|YSZ|SCFO:YSZ(7:3) symmetrical cell under the same conditions.

  7. Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

    SciTech Connect

    Maghzi, Shawn; Subramanian, Ramanathan; Rizeq, George; Singh, Surinder; McDermott, John; Eiteneer, Boris; Ladd, David; Vazquez, Arturo; Anderson, Denise; Bates, Noel

    2011-09-30

    The U.S. Department of Energy‘s National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE‘s bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation, and

  8. Product Characterization for Entrained Flow Coal/Biomass Co-Gasification

    SciTech Connect

    Maghzi, Shawn; Subramanian, Ramanathan; Rizeq, George; Singh, Surinder; McDermott, John; Eiteneer, Boris; Ladd, David; Vazquez, Arturo; Anderson, Denise; Bates, Noel

    2011-12-11

    The U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. This interest is primarily motivated by the need to increase energy security and reduce greenhouse gas emissions in the United States. Gasification technologies represent clean, flexible and efficient conversion pathways to utilize coal and biomass resources. Substantial experience and knowledge had been developed worldwide on gasification of either coal or biomass. However, reliable data on effects of blending various biomass fuels with coal during gasification process and resulting syngas composition are lacking. In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. This work was performed using a bench-scale gasifier (BSG) and a pilot-scale entrained flow gasifier (EFG). This project focused on comprehensive characterization of the products from gasifying coal/biomass mixtures in a high-temperature, high-pressure entrained flow gasifier. Results from this project provide guidance on appropriate gas clean-up systems and optimization of operating parameters needed to develop and commercialize gasification technologies. GE's bench-scale test facility provided the bulk of high-fidelity quantitative data under temperature, heating rate, and residence time conditions closely matching those of commercial oxygen-blown entrained flow gasifiers. Energy and Environmental Research Center (EERC) pilot-scale test facility provided focused high temperature and pressure tests at entrained flow gasifier conditions. Accurate matching of syngas time-temperature history during cooling ensured that complex species interactions including homogeneous and heterogeneous processes such as particle nucleation, coagulation, surface condensation, and gas

  9. Refractive index matched suspensions as a tool for investigating entrainment by avalanches and debris flows

    NASA Astrophysics Data System (ADS)

    Bates, Belinda; Ancey, Christophe

    2015-04-01

    Geophysical gravity flows such as avalanches and debris flows are complicated mixtures of fluid and solids, often containing particle sizes of many orders of magnitude. In a debris flow, for example, the composition varies from head to tail, and from bottom to top due to particle size segregation and recirculation. In addition the solid components may have different masses and mechanical properties. For this reason, a complete understanding of substrate entrainment by this type of flow is still out of reach. A common strategy for advancing our understanding of the physics of processes like entrainment is to use a greatly simplified laboratory model of a debris flow, and take internal and bulk measurements. This idealized technique forms the basis of this study, in which a two-phase, monodisperse suspension of PMMA beads in a refractive-index matched suspending fluid flowed down a flume, encountering an entrainable region of the same suspension on the way. This study represents the first attempt of taking continuous internal velocity measurements inside a flowing, entraining model avalanche or debris flow in the laboratory. Interior PIV measurements of flow velocity were taken in the entrainable region, along with surface height measurements, to shed some light on the entrainment mechanisms and to see how the bulk flow responded. Further, some differential pressure measurements were made in the entrainable bed to see if pore-pressure peaks had any correlation with significant events during entrainment. We present our preliminary findings and discuss the suitability of the method to entrainment investigations.

  10. Fuel ethanol production from crop residues and processing byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2007, the production of fuel ethanol from corn starch reached 6.5 billion gallons in the U.S.A. Various crop residues such as corn stover, wheat straw, and barley straw, and crop processing byproducts such as corn fiber and rice hulls can serve as low-cost lignocellulosic feedstocks for conversi...

  11. 76 FR 44049 - Guidance for Fuel Cycle Facility Change Processes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... COMMISSION Guidance for Fuel Cycle Facility Change Processes AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide; extension of comment period. SUMMARY: On July 14, 2011 (76 FR 41527), the U.S...: Richard.Jervey@nrc.gov . SUPPLEMENTARY INFORMATION: On July 14, 2011 (76 FR 41527), the NRC published...

  12. FUEL ETHANOL PRODUCTION FROM AGRICULTURAL RESIDUES AND PROCESSING BYPRODUCTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2005, the production of fuel ethanol from corn starch reached 4.5 billion gallons in the U.S. Various agricultural residues such as corn stover and wheat straw, and agricultural processing byproducts such as corn fiber and rice hulls, can serve as low-cost lignocellulosic feedstocks for conversi...

  13. Fate of virginiamycin through the fuel ethanol production process

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antibiotics are frequently used to prevent and treat bacterial contamination of commercial fuel ethanol fermentations, but there is concern that antibiotic residues may persist in the distillers grains coproducts. A study to evaluate the fate of virginiamycin during the ethanol production process wa...

  14. PROCESS OF DISSOLVING FUEL ELEMENTS OF NUCLEAR REACTORS

    DOEpatents

    Wall, E.M.V.; Bauer, D.T.; Hahn, H.T.

    1963-09-01

    A process is described for dissolving stainless-steelor zirconium-clad uranium dioxide fuel elements by immersing the elements in molten lead chloride, adding copper, cuprous chloride, or cupric chloride as a catalyst and passing chlorine through the salt mixture. (AEC)

  15. On robustness of phase resetting to cell division under entrainment.

    PubMed

    Ahmed, Hafiz; Ushirobira, Rosane; Efimov, Denis

    2015-12-21

    The problem of phase synchronization for a population of genetic oscillators (circadian clocks, synthetic oscillators, etc.) is considered in this paper, taking into account a cell division process and a common entrainment input in the population. The proposed analysis approach is based on the Phase Response Curve (PRC) model of an oscillator (the first order reduced model obtained for the linearized system and inputs with infinitesimal amplitude). The occurrence of cell division introduces state resetting in the model, placing it in the class of hybrid systems. It is shown that without common entraining input in all oscillators, the cell division acts as a disturbance causing phase drift, while the presence of entrainment guarantees boundedness of synchronization phase errors in the population. The performance of the obtained solutions is demonstrated via computer experiments for two different models of circadian/genetic oscillators (Neurospora׳s circadian oscillation model and the repressilator). PMID:26463679

  16. Method For Processing Spent (Trn,Zr)N Fuel

    DOEpatents

    Miller, William E.; Richmann, Michael K.

    2004-07-27

    A new process for recycling spent nuclear fuels, in particular, mixed nitrides of transuranic elements and zirconium. The process consists of two electrorefiner cells in series configuration. A transuranic element such as plutonium is reduced at the cathode in the first cell, zirconium at the cathode in the second cell, and nitrogen-15 is released and captured for reuse to make transuranic and zirconium nitrides.

  17. Observing of entrainment using small UAS

    NASA Astrophysics Data System (ADS)

    Martin, S.; Bange, J.; Beyrich, F.

    2012-04-01

    Entrainment processes between the atmospheric boundary layer and the free atmosphere are important concerning vertical exchange of momentum, energy, water vapor, trace gases and aerosol. The transition zone between the convectively mixed boundary layer and the stably stratified free atmosphere is called the entrainment zone (EZ). The EZ restrains the domain of turbulence by a temperature inversion and acts as a lid to pollutants. Measurement flights of the mini meteorological aerial vehicle (M2AV) of the Technische Universität Braunschweig were performed in spring 2011 to determine the capability of the unmanned aerial system (UAS) to measure the structure of the EZ. The campaign took place at the Meteorological Observatory Lindenberg / Richard-Aßmann-Observatory of the German Meteorological Service, which is located close to Berlin. Besides the M2AV flights, standard observations were performed by a 12 m and 99 m tower, a sodar, ceilometer and radiosondes. A tethered balloon with measurement units at six different levels was operated especially for this campaign. The measurements of these systems were used to determine the inversion layer and to capture its diurnal cycle. The talk will be focused on vertical profiles of the M2AV up to the free atmosphere, detailed analysis of spatial series of w'θ' at different altitudes and on vertical profiles of normalized variances of the vertical wind component and the potential temperature.

  18. Process gases for high velocity oxy-fuel thermal spraying

    SciTech Connect

    Creffield, G.K.; Chapman, I.F.; Cole, M.A.; Page, W.J.; McDonough, T.

    1994-12-31

    The importance of fuel and other process gases for high velocity oxy-fuel (HVOF) thermal spraying and especially the delivery of them to the point of use is well recognized. Problems associated with the supply of liquid fuel gases, at the high flow rates and pressures required by this process, have been addressed. Considerable development work has gone into designing an appropriate liquid withdrawal and vaporizer system for propylene, which overcomes these previous difficulties and enables users to maintain adequate fuel gas flow rates in order to ensure optimum operating conditions for the production of high quality coatings. A feature of the thermal spray process is that the temperature of the workpiece is kept low, typically below 150 C, in order to reduce residual stresses in the coating and to protect heat sensitive substrates. Traditionally this has been by compressed air, however, improved cooling has been achieved using carbon dioxide. Specially designed equipment is now available which provides and directs a cold mixture of carbon dioxide gas and solid particles (snow) via suitable nozzles, on the workpiece. The position of the cooling stream can be varied, depending on the application. These developments emphasize the importance now attached to providing dedicated gas installation packages for HVOF.

  19. Coal liquefaction process wherein jet fuel, diesel fuel and/or ASTM No. 2 fuel oil is recovered

    DOEpatents

    Bauman, Richard F.; Ryan, Daniel F.

    1982-01-01

    An improved process for the liquefaction of coal and similar solid carbonaceous materials wherein a hydrogen donor solvent or diluent derived from the solid carbonaceous material is used to form a slurry of the solid carbonaceous material and wherein the naphthenic components from the solvent or diluent fraction are separated and used as jet fuel components. The extraction increases the relative concentration of hydroaromatic (hydrogen donor) components and as a result reduces the gas yield during liquefaction and decreases hydrogen consumption during said liquefaction. The hydrogenation severity can be controlled to increase the yield of naphthenic components and hence the yield of jet fuel and in a preferred embodiment jet fuel yield is maximized while at the same time maintaining solvent balance.

  20. Used nuclear fuel separations process simulation and testing

    SciTech Connect

    Pereira, C.; Krebs, J.F.; Copple, J.M.; Frey, K.E.; Maggos, L.E.; Figueroa, J.; Willit, J.L.; Papadias, D.D.

    2013-07-01

    Recent efforts in separations process simulation at Argonne have expanded from the traditional focus on solvent extraction flowsheet design in order to capture process dynamics and to simulate other components, processing and systems of a used nuclear fuel reprocessing plant. For example, the Argonne Model for Universal Solvent Extraction (AMUSE) code has been enhanced to make it both more portable and more readily extensible. Moving away from a spreadsheet environment makes the addition of new species and processes simpler for the expert user, which should enable more rapid implementation of chemical models that simulate evolving processes. The dyAMUSE (dynamic AMUSE) version allows the simulation of transient behavior across an extractor. Electrochemical separations have now been modeled using spreadsheet codes that simulate the electrochemical recycle of fast reactor fuel. The user can follow the evolution of the salt, products, and waste compositions in the electro-refiner, cathode processors, and drawdown as a function of fuel batches treated. To further expand capabilities in integrating multiple unit operations, a platform for linking mathematical models representing the different operations that comprise a reprocessing facility was adapted to enable systems-level analysis and optimization of facility functions. (authors)

  1. Holes and Entrainment in Stratocumulus.

    NASA Astrophysics Data System (ADS)

    Gerber, H.; Frick, G.; Malinowski, S. P.; Brenguier, J.-L.; Burnet, F.

    2005-02-01

    Aircraft flights through stratocumulus clouds (Sc) during the Dynamics and Chemistry of Marine Stratocumulus II (DYCOMS-II) study off the California coast found narrow in-cloud regions with less liquid water content (LWC) and cooler temperatures than average background values. The regions are named cloud holes and are assumed to be a result of water evaporated by the entrainment of dryer air from above the Sc. While such features have been noted previously, this study provided a unique opportunity to investigate in much greater detail the nature of the holes, as well as their relationship to the entrainment rate, because high-speed temperature and LWC probes with maximum spatial resolution of 10 cm were flown together for the first time. Nine long-duration flights were made through mostly unbroken Sc for which conditional sampling was used to identify the location and size of the holes. The holes are concentrated near cloud top, their average width near cloud top is about 5 m, their relative length distribution is nearly constant for all flights, and they can penetrate hundreds of meters deep into the Sc before being lost by mixing. Entrainment velocities at cloud top are estimated from measurements of fluxes of reduced LWC and vapor mixing ratios in holes, the fraction of cloud area covered by holes, and the total water jump between cloud top and the free atmosphere. Rates as large as 10 mm s-1 are found for nocturnal flights, and these rates are about 3 times larger than for daytime flight segments. The rates correlate best with the size of the buoyancy jump above the Sc; the present conditional-sampling approach for measuring the rates gives larger rates than the "flux jump" rates determined by others for the same flights by a factor of about 2. The stability criterion for all Sc predicts thinning and breakup of the Sc, which does not occur. The minimal amount of cloud-top evaporative cooling caused by entrainment contributes little to the top-down convection

  2. Crustal entrainment and pulsar glitches.

    PubMed

    Chamel, N

    2013-01-01

    Large pulsar frequency glitches are generally interpreted as sudden transfers of angular momentum between the neutron superfluid permeating the inner crust and the rest of the star. Despite the absence of viscous drag, the neutron superfluid is strongly coupled to the crust due to nondissipative entrainment effects. These effects are shown to severely limit the maximum amount of angular momentum that can possibly be transferred during glitches. In particular, it is found that the glitches observed in the Vela pulsar require an additional reservoir of angular momentum. PMID:23383772

  3. Fuel processing for PEM fuel cells: transport and kinetic issues of system design

    NASA Astrophysics Data System (ADS)

    Zalc, J. M.; Löffler, D. G.

    In light of the distribution and storage issues associated with hydrogen, efficient on-board fuel processing will be a significant factor in the implementation of PEM fuel cells for automotive applications. Here, we apply basic chemical engineering principles to gain insight into the factors that limit performance in each component of a fuel processor. A system consisting of a plate reactor steam reformer, water-gas shift unit, and preferential oxidation reactor is used as a case study. It is found that for a steam reformer based on catalyst-coated foils, mass transfer from the bulk gas to the catalyst surface is the limiting process. The water-gas shift reactor is expected to be the largest component of the fuel processor and is limited by intrinsic catalyst activity, while a successful preferential oxidation unit depends on strict temperature control in order to minimize parasitic hydrogen oxidation. This stepwise approach of sequentially eliminating rate-limiting processes can be used to identify possible means of performance enhancement in a broad range of applications.

  4. The Stochastic Parcel Model: A deterministic parameterization of stochastically entraining convection

    NASA Astrophysics Data System (ADS)

    Romps, David M.

    2016-03-01

    Convective entrainment is a process that is poorly represented in existing convective parameterizations. By many estimates, convective entrainment is the leading source of error in global climate models. As a potential remedy, an Eulerian implementation of the Stochastic Parcel Model (SPM) is presented here as a convective parameterization that treats entrainment in a physically realistic and computationally efficient way. Drawing on evidence that convecting clouds comprise air parcels subject to Poisson-process entrainment events, the SPM calculates the deterministic limit of an infinite number of such parcels. For computational efficiency, the SPM groups parcels at each height by their purity, which is a measure of their total entrainment up to that height. This reduces the calculation of convective fluxes to a sequence of matrix multiplications. The SPM is implemented in a single-column model and compared with a large-eddy simulation of deep convection.

  5. Optimal entrainment of heterogeneous noisy neurons

    PubMed Central

    Wilson, Dan; Holt, Abbey B.; Netoff, Theoden I.; Moehlis, Jeff

    2015-01-01

    We develop a methodology to design a stimulus optimized to entrain nonlinear, noisy limit cycle oscillators with uncertain properties. Conditions are derived which guarantee that the stimulus will entrain the oscillators despite these uncertainties. Using these conditions, we develop an energy optimal control strategy to design an efficient entraining stimulus and apply it to numerical models of noisy phase oscillators and to in vitro hippocampal neurons. In both instances, the optimal stimuli outperform other similar but suboptimal entraining stimuli. Because this control strategy explicitly accounts for both noise and inherent uncertainty of model parameters, it could have experimental relevance to neural circuits where robust spike timing plays an important role. PMID:26074762

  6. Analysis of on-board fuel processing designs for PEM fuel cell vehicles

    SciTech Connect

    Kartha, S.; Fischer, S.; Kreutz, T.

    1996-12-31

    As a liquid fuel with weight and volume energy densities comparable to those of gasoline, methanol is an attractive energy carrier for mobile power systems. It is available without contaminants such as sulfur, and can be easily reformed at relatively low temperatures with inexpensive catalysts. This study is concerned with comparing the net efficiencies of PEM fuel cell vehicles fueled with methanol and hydrogen, using fuel cell system models developed using ASPEN chemical process simulation software. For both the methanol and hydrogen systems, base case designs are developed and several variations are considered that differ with respect to the degree of system integration for recovery of heat and compressive work. The methanol systems are based on steam reforming with the water-gas shift reaction and preferential oxidation, and the hydrogen systems are based on compressed hydrogen. This analysis is an exercise in optimizing the system design for each fuel, which ultimately entails balancing system efficiency against a host of other considerations, including system complexity, performance, cost, reliability, weight and volume.

  7. Process development and fabrication for sphere-pac fuel rods. [PWR; BWR

    SciTech Connect

    Welty, R.K.; Campbell, M.H.

    1981-06-01

    Uranium fuel rods containing sphere-pac fuel have been fabricated for in-reactor tests and demonstrations. A process for the development, qualification, and fabrication of acceptable sphere-pac fuel rods is described. Special equipment to control fuel contamination with moisture or air and the equipment layout needed for rod fabrication is described and tests for assuring the uniformity of the fuel column are discussed. Fuel retainers required for sphere-pac fuel column stability and instrumentation to measure fuel column smear density are described. Results of sphere-pac fuel rod fabrication campaigns are reviewed and recommended improvements for high throughput production are noted.

  8. FUEL ELEMENTS FOR NUCLEAR REACTORS AND PROCESS OF MAKING

    DOEpatents

    Roake, W.E.

    1958-08-19

    A process is described for producing uranium metal granules for use in reactor fuel elements. The granules are made by suspending powdered uramiunn metal or uranium hydride in a viscous, non-reactive liquid, such as paraffin oil, aad pouring the resulting suspension in droplet, on to a bed of powdered absorbent. In this manner the liquid vehicle is taken up by the sorbent and spherical pellets of uranium metal are obtained. The

  9. Modular, High-Volume Fuel Cell Leak-Test Suite and Process

    SciTech Connect

    Ru Chen; Ian Kaye

    2012-03-12

    Fuel cell stacks are typically hand-assembled and tested. As a result the manufacturing process is labor-intensive and time-consuming. The fluid leakage in fuel cell stacks may reduce fuel cell performance, damage fuel cell stack, or even cause fire and become a safety hazard. Leak check is a critical step in the fuel cell stack manufacturing. The fuel cell industry is in need of fuel cell leak-test processes and equipment that is automatic, robust, and high throughput. The equipment should reduce fuel cell manufacturing cost.

  10. Femtosecond laser processing of fuel injectors - a materials processing evaluation

    SciTech Connect

    Stuart, B C; Wynne, A

    2000-12-16

    Lawrence Livermore National Laboratory (LLNL) has developed a new laser-based machining technology that utilizes ultrashort-pulse (0.1-1.0 picosecond) lasers to cut materials with negligible generation of heat or shock. The ultrashort pulse laser, developed for the Department of Energy (Defense Programs) has numerous applications in operations requiring high precision machining. Due to the extremely short duration of the laser pulse, material removal occurs by a different physical mechanism than in conventional machining. As a result, any material (e.g., hardened steel, ceramics, diamond, silicon, etc.) can be machined with minimal heat-affected zone or damage to the remaining material. As a result of the threshold nature of the process, shaped holes, cuts, and textures can be achieved with simple beam shaping. Conventional laser tools used for cutting or high-precision machining (e.g., sculpting, drilling) use long laser pulses (10{sup -8} to over 1 sec) to remove material by heating it to the melting or boiling point (Figure 1.1a). This often results in significant damage to the remaining material and produces considerable slag (Figure 1.2a). With ultrashort laser pulses, material is removed by ionizing the material (Figure 1.1b). The ionized plasma expands away from the surface too quickly for significant energy transfer to the remaining material. This distinct mechanism produces extremely precise and clean-edged holes without melting or degrading the remaining material (Figures 1.2 and 1.3). Since only a very small amount of material ({approx} <0.5 microns) is removed per laser pulse, extremely precise machining can be achieved. High machining speed is achieved by operating the lasers at repetition rates up to 10,000 pulses per second. As a diagnostic, the character of the short-pulse laser produced plasma enables determination of the material being machined between pulses. This feature allows the machining of multilayer materials, metal on metal or metal on

  11. Understanding the transport processes in polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Cheah, May Jean

    Polymer electrolyte membrane (PEM) fuel cells are energy conversion devices suitable for automotive, stationary and portable applications. An engineering challenge that is hindering the widespread use of PEM fuel cells is the water management issue, where either a lack of water (resulting in membrane dehydration) or an excess accumulation of liquid water (resulting in fuel cell flooding) critically reduces the PEM fuel cell performance. The water management issue is addressed by this dissertation through the study of three transport processes occurring in PEM fuel cells. Water transport within the membrane is a combination of water diffusion down the water activity gradient and the dragging of water molecules by protons when there is a proton current, in a phenomenon termed electro-osmotic drag, EOD. The impact of water diffusion and EOD on the water flux across the membrane is reduced due to water transport resistance at the vapor/membrane interface. The redistribution of water inside the membrane by EOD causes an overall increase in the membrane resistance that regulates the current and thus EOD, thereby preventing membrane dehydration. Liquid water transport in the PEM fuel cell flow channel was examined at different gas flow regimes. At low gas Reynolds numbers, drops transitioned into slugs that are subsequently pushed out of the flow channel by the gas flow. The slug volume is dependent on the geometric shape, the surface wettability and the orientation (with respect to gravity) of the flow channel. The differential pressure required for slug motion primarily depends on the interfacial forces acting along the contact lines at the front and the back of the slug. At high gas Reynolds number, water is removed as a film or as drops depending on the flow channel surface wettability. The shape of growing drops at low and high Reynolds number can be described by a simple interfacial energy minimization model. Under flooding conditions, the fuel cell local current

  12. Investigation of GdBaCo2-xFexO6-δ (x = 0, 0.2) - Ce0.8Sm0.2O2 composite cathodes for intermediate temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Tsvetkova, N. S.; Zuev, A. Yu.; Tsvetkov, D. S.

    2013-12-01

    The double perovskites GdBaCo2-xFexO6-δ (x = 0, 0.2) and composites (100 - y) GdBaCo2-xFexO6-δ (x = 0, 0.2) - y Ce0.8Sm0.2O2 (y = 10-50 wt.%) were investigated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). Chemical compatibility of GdBaCo2-xFexO6-δ (x = 0, 0.2) with solid electrolyte Ce0.8Sm0.2O2, thermal expansion, DC conductivity and electrochemical performance of (100 - y) GdBaCo2-xFexO6-δ (x = 0, 0.2) - y Ce0.8Sm0.2O2 (y = 10-50 wt.%) were studied. Partial substitution of Fe for Co was shown to lead to decrease of double perovskite GdBaCo2-xFexO6-δ reactivity with the solid electrolyte Ce0.8Sm0.2O2. Polarization resistance of cathodes studied was found to depend significantly on firing temperature. Variation of solid electrolyte content in (100 - y) GdBaCo2-xFexO6-δ (x = 0, 0.2) - y Ce0.8Sm0.2O2 (y = 10-50 wt.%) composites was shown to allow to optimize their electrochemical performance. Cathode materials of 80 wt.% GdBaCo2O6-δ - 20 wt.% Ce0.8Sm0.2O2 and 65 wt.% GdBaCo1.8Fe0.2O6-δ - 35 wt.% Ce0.8Sm0.2O2 were found to have the lowest polarization resistances and reasonable values of thermal expansion coefficient (TEC) and, therefore, can be considered as promising cathode materials for IT-SOFCs.

  13. Scalar entrainment in the mixing layer

    NASA Technical Reports Server (NTRS)

    Sandham, N. D.; Mungal, M. G.; Broadwell, J. E.; Reynolds, W. C.

    1988-01-01

    New definitions of entrainment and mixing based on the passive scalar field in the plane mixing layer are proposed. The definitions distinguish clearly between three fluid states: (1) unmixed fluid, (2) fluid engulfed in the mixing layer, trapped between two scalar contours, and (3) mixed fluid. The difference betwen (2) and (3) is the amount of fluid which has been engulfed during the pairing process, but has not yet mixed. Trends are identified from direct numerical simulations and extensions to high Reynolds number mixing layers are made in terms of the Broadwell-Breidenthal mixing model. In the limit of high Peclet number (Pe = ReSc) it is speculated that engulfed fluid rises in steps associated with pairings, introducing unmixed fluid into the large scale structures, where it is eventually mixed at the Kolmogorov scale. From this viewpoint, pairing is a prerequisite for mixing in the turbulent plane mixing layer.

  14. Characteristics of air entrainment during dynamic wetting failure along a planar substrate

    NASA Astrophysics Data System (ADS)

    Kumar, Satish; Vandre, Eric; Carvalho, Marcio

    2014-11-01

    We report results of experiments characterizing the onset of air entrainment during dynamic wetting failure along a planar substrate (J. Fluid Mech. 747, 119 (2014)). Using high-speed video, dynamic contact line (DCL) behavior is recorded as a tape substrate is drawn through a bath of a glycerol/water solution. Air entrainment is identified by triangular air films that elongate from the DCL above a critical substrate speed. Meniscus confinement between the substrate and a stationary plate delays air entrainment to higher speeds for a wide range of liquid viscosities. Liquid pressurization moves the meniscus near a sharp corner, changing its shape and further postponing air entrainment. Meniscus shapes recorded near the DCL demonstrate that smaller entrained air films appear in the more viscous solutions. Regardless of size, air films become unstable to thickness perturbations and ultimately rupture, leading to entrainment of air bubbles. Recorded critical speeds and air-film sizes compare well to predictions from a hydrodynamic model for dynamic wetting failure, indicating that strong air stresses near the DCL trigger the onset of air entrainment. The results suggest strategies for postponing air entrainment, which often limits the maximum speed of industrial coating processes.

  15. Process for producing fuel from plant sources and fuel blends containing same

    SciTech Connect

    Whitworth, R.D.

    1987-04-04

    A process for producing a fuel from plant sources comprising the steps of: (a) providing a supply of limonene; (b) distilling the limonene and removing the distillate fraction in a temperature range of from about 346/sup 0/F to about 382/sup 0/F; (c) removing water from the distilled limonene; and (d) treating the distilled limonene to preclude the formation of gums therefrom.

  16. Process for converting cellulosic materials into fuels and chemicals

    DOEpatents

    Scott, Charles D.; Faison, Brendlyn D.; Davison, Brian H.; Woodward, Jonathan

    1994-01-01

    A process for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system.

  17. Laboratory experiments on stability and entrainment of oceanic stratocumulus. Part 2: Entrainment experiment

    NASA Technical Reports Server (NTRS)

    Shy, Shenqyang S.

    1990-01-01

    A stratified interface is stable to the buoyancy reversal instability for surprisingly large values of D (buoyancy reversal parameter). A new instability mechanism is proposed, which considers the mixing process at the interface. For the type of density curves studied here, under strong perturbations, the mixed parcel must have a buoyancy reversal comparable to the initial stratification before the interface is unstable. This is in accord with a simple model of the interface mixing process, as well as aircraft observations of long-live marine stratocumulus clouds. These clouds' remarkable longevity in the face of finite D indicates that they can be stable (Hanson, 1984; Albrecht et al., 1985; Siems et al., 1989). It is suggested that buoyancy reversal as well as the disturbance must be large for Cloudtop Entrainment Stability. The effect of buoyancy reversal (evaporative cooling) does not always enhance the entrainment rate over that in the inert case, but it may be negligible if Ri (Richardson number) is large (Ri is larger than 50) and D is small (D is smaller than 0.5). This work may shed some light on the fundamental mechanism of the breakup process of the subtropical stratocumulus clouds into tradewind cumulus. These results may also be related to the instability in the Weddell Sea off of Antarctica.

  18. Integration and testing of hot desulfurization and entrained-flow gasification for power generation systems. Phase 2, Process optimization: Volume 1, Program summary and PDU operations

    SciTech Connect

    Robin, A.M.; Kassman, J.S.; Leininger, T.F.; Wolfenbarger, J.K.; Wu, C.M.; Yang, P.P.

    1991-09-01

    This second Topical Report describes the work that was completed between January 1, 1989 and December 31, 1990 in a Cooperative Agreement between Texaco and the US Department of Energy that began on September 30, 1987. During the period that is covered in this report, the development and optimization of in-situ and external desulfurization processes were pursued. The research effort included bench scale testing, PDU scoping tests, process economic studies and advanced instrument testing. Two bench scale studies were performed at the Research Triangle Institute with zinc titanate sorbent to obtain data on its cycle life, sulfur capacity, durability and the effect of chlorides. These studies quantify sulfur capture during simulated air and oxygen-blown gasification for two zinc titanate formulations. Eight PDU runs for a total of 20 days of operation were conducted to evaluate the performance of candidate sorbents for both in-situ and external desulfurization. A total of 47 tests were completed with oxygen and air-blown gasification. Candidate sorbents included iron oxide for in-situ desulfurization and calcium based and mixed metal oxides for external desulfurization. Gasifier performance and sorbent sulfur capture are compared for both air-blown and oxygen-blown operation.

  19. Actinide partitioning processes for fuel reprocessing and refabrication plant wastes

    SciTech Connect

    Finney, B.C.; Tedder, D.W.

    1980-01-01

    Chemical processing methods have been developed on a laboratory scale to partition the actinides from the liquid and solid fuel reprocessing plant (FRP) and refabrication plant (FFP) wastes. It was envisioned that these processes would be incorporated into separate waste treatment facilities (WTFs) that are adjacent to, but not integrated with, the fuel reprocessing and refabrication plants. Engineering equipment and material balance flowsheets have been developed for WTFs in support of a 2000-MTHM/year FRP and a 660-MTHM/year MOX-FFP. The processing subsystems incorporated in the FRP-WTF are: High-Level Solid Waste Treatment, High-Level Liquid Waste Treatment, Solid Alpha Waste Treatment, Cation Exchange Chromatography, Salt Waste Treatment, Actinide Recovery, Solvent Cleanup and recycle, Off-Gas Treatment, Actinide Product Concentration, and Acid and Water Recycle. The WTF supporting a fuel refabrication facility, although similar, does not contain subsystems (1) and (2). Based on the results of the laboratory and hot-cell experimental work, we believe that the processes and flowsheets offer the potential to reduce the total unrecovered actinides in FRP and FFP wastes to less than or equal to 0.25%. The actinide partitioning processes and the WTF concept represent advanced technology that would require substantial work before commercialization. It is estimated that an orderly development program would require 15 to 20 years to complete and would cost about 700 million 1979 dollars. It is estimated that the capital cost and annual operating cost, in mid-1979 dollars, for the FRP-WTF are $1035 million and $71.5 million/year, and for the FFP-WTF are $436 million and $25.6 million/year, respectively.

  20. Scale dependence of entrainment-mixing mechanisms in cumulus clouds

    DOE PAGESBeta

    Lu, Chunsong; Liu, Yangang; Niu, Shengjie; Endo, Satoshi

    2014-12-17

    This work empirically examines the dependence of entrainment-mixing mechanisms on the averaging scale in cumulus clouds using in situ aircraft observations during the Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. A new measure of homogeneous mixing degree is defined that can encompass all types of mixing mechanisms. Analysis of the dependence of the homogenous mixing degree on the averaging scale shows that, on average, the homogenous mixing degree decreases with increasing averaging scales, suggesting that apparent mixing mechanisms gradually approach from homogeneous mixing to extreme inhomogeneous mixing with increasingmore » scales. The scale dependence can be well quantified by an exponential function, providing first attempt at developing a scale-dependent parameterization for the entrainment-mixing mechanism. The influences of three factors on the scale dependence are further examined: droplet-free filament properties (size and fraction), microphysical properties (mean volume radius and liquid water content of cloud droplet size distributions adjacent to droplet-free filaments), and relative humidity of entrained dry air. It is found that the decreasing rate of homogeneous mixing degree with increasing averaging scales becomes larger with larger droplet-free filament size and fraction, larger mean volume radius and liquid water content, or higher relative humidity. The results underscore the necessity and possibility of considering averaging scale in representation of entrainment-mixing processes in atmospheric models.« less

  1. Scale dependence of entrainment-mixing mechanisms in cumulus clouds

    SciTech Connect

    Lu, Chunsong; Liu, Yangang; Niu, Shengjie; Endo, Satoshi

    2014-12-17

    This work empirically examines the dependence of entrainment-mixing mechanisms on the averaging scale in cumulus clouds using in situ aircraft observations during the Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) field campaign. A new measure of homogeneous mixing degree is defined that can encompass all types of mixing mechanisms. Analysis of the dependence of the homogenous mixing degree on the averaging scale shows that, on average, the homogenous mixing degree decreases with increasing averaging scales, suggesting that apparent mixing mechanisms gradually approach from homogeneous mixing to extreme inhomogeneous mixing with increasing scales. The scale dependence can be well quantified by an exponential function, providing first attempt at developing a scale-dependent parameterization for the entrainment-mixing mechanism. The influences of three factors on the scale dependence are further examined: droplet-free filament properties (size and fraction), microphysical properties (mean volume radius and liquid water content of cloud droplet size distributions adjacent to droplet-free filaments), and relative humidity of entrained dry air. It is found that the decreasing rate of homogeneous mixing degree with increasing averaging scales becomes larger with larger droplet-free filament size and fraction, larger mean volume radius and liquid water content, or higher relative humidity. The results underscore the necessity and possibility of considering averaging scale in representation of entrainment-mixing processes in atmospheric models.

  2. The neurochemical basis of photic entrainment of the circadian pacemaker

    NASA Technical Reports Server (NTRS)

    Rea, Michael A.; Buckley, Becky; Lutton, Lewis M.

    1992-01-01

    Circadian rhythmicity in mammals is controlled by the action of a light-entrainable hypothalamus, in association with two cell clusters known as the supra chiasmatic nuclei (SCN). In the absence of temporal environmental clues, this pacemaker continues to measure time by an endogenous mechanism (clock), driving biochemical, physiological, and behavioral rhythms that reflect the natural period of the pacemaker oscillation. This endogenous period usually differs slightly from 24 hours (i.e., circadian). When mammals are maintained under a 24 hour light-dark (LD) cycle, the pacemaker becomes entrained such that the period of the pacemaker oscillation matches that of the LD cycle. Potentially entraining photic information is conveyed to the SCN via a direct retinal projection, the retinohypothalamic tract (RHT). RHT neurotransmission is thought to be mediated by the release of excitatory amino acids (EAA) in the SCN. In support of this hypothesis, recent experiments using nocturnal rodents have shown that EAA antagonists block the effects of light on pacemaker-driven behavioral rhythms, and attenuate light induced gene expression in SCN cells. An understanding of the neurochemical basis of the photic entrainment process would facilitate the development of pharmacological strategies for maintaining synchrony among shift workers in environments, such as the Space Station, which provide unreliable or conflicting temporal photic clues.

  3. Synthesis and electrochemical characterization of Sr2Fe1.5Mo0.5O6-Sm0.2Ce0.8O1.9 composite cathode for intermediate-temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Dai, Ningning; Lou, Zhongliang; Wang, Zhenhua; Liu, Xiaoxi; Yan, Yiming; Qiao, Jinshuo; Jiang, Taizhi; Sun, Kening

    2013-12-01

    Nanoporous composite oxides Sr2Fe1.5Mo0.5O6-Sm0.2Ce0.8O1.9 (SFM-SDC) have been prepared by a facile one-step method as cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The SFM-SDC composite materials have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM) and electrochemical impedance spectroscopy (EIS). The EIS results exhibit that SFM-SDC40 (wt% 60:40) cathode has encouraging electrochemical performance with low polarization resistance (Rp) on YSZ (Y2O3-stabilized ZrO2) electrolyte. Subsequently, bi-layer cathodes SDC/SFM-SDC are fabricated, and excellent electrochemical performance of such composite cathodes are observed. We demonstrate that the SDC interlayer significantly decreases the Rp of cathode and accelerates the charge transfer process. As a result, the Rp of the SDC/SFM-SDC40 bi-layer cathodes is almost 50% less than that of SFM-SDC40 cathode on YSZ electrolyte at 800 °C, and Rp is only 0.11 Ω cm2. Compared with single cells without an interlayer, the anode-supported single cells with SDC interlayer exhibit enhancement in overall power performance.

  4. A survey of processes for producing hydrogen fuel from different sources for automotive-propulsion fuel cells

    SciTech Connect

    Brown, L.F.

    1996-03-01

    Seven common fuels are compared for their utility as hydrogen sources for proton-exchange-membrane fuel cells used in automotive propulsion. Methanol, natural gas, gasoline, diesel fuel, aviation jet fuel, ethanol, and hydrogen are the fuels considered. Except for the steam reforming of methanol and using pure hydrogen, all processes for generating hydrogen from these fuels require temperatures over 1000 K at some point. With the same two exceptions, all processes require water-gas shift reactors of significant size. All processes require low-sulfur or zero-sulfur fuels, and this may add cost to some of them. Fuels produced by steam reforming contain {approximately}70-80% hydrogen, those by partial oxidation {approximately}35-45%. The lower percentages may adversely affect cell performance. Theoretical input energies do not differ markedly among the various processes for generating hydrogen from organic-chemical fuels. Pure hydrogen has severe distribution and storage problems. As a result, the steam reforming of methanol is the leading candidate process for on-board generation of hydrogen for automotive propulsion. If methanol unavailability or a high price demands an alternative process, steam reforming appears preferable to partial oxidation for this purpose.

  5. Fast biomass pyrolysis with an entrained-flow reactor

    NASA Astrophysics Data System (ADS)

    Bohn, M. S.; Benham, C.

    1982-02-01

    A tubular entrained flow reactor has been used to study the effect of process control variables on fast biomass pyrolysis. In this type of reactor, finely ground biomass particles are entrained by carrier gas and transported through a reactor tube which is heated to about 900 C. Biomass particles pyrolyze as a result of heat transfer from the reactor wall yielding a gas composed primarily of carbon monoxide, carbon dioxide, hydrogen, methane, and unsaturated hydrocarbons. In this experimental program three dependent variables, percent conversion to gas, gas composition, and process heat, have been measured as a function of several process control variables. These process variables include reactor temperature, carrier gas to biomass flow ratio, reactor residence time, biomass particle size, and reactor Reynolds number. The data allow one to design and predict the performance of large scale reactors and also elucidates heat transfer mechanisms in fast biomass pyrolysis.

  6. Technical and regulatory review of the Rover nuclear fuel process for use on Fort St. Vrain fuel

    SciTech Connect

    Hertzler, T. )

    1993-02-01

    This report describes the results of an analysis for processing and final disposal of Fort St. Vrain (FSV) irradiated fuel in Rover-type equipment or technologies. This analysis includes an evaluation of the current Rover equipment status and the applicability of this technology in processing FSV fuel. The analyses are based on the physical characteristics of the FSV fuel and processing capabilities of the Rover equipment. Alternate FSV fuel disposal options are also considered including fuel-rod removal from the block, disposal of the empty block, or disposal of the entire fuel-containing block. The results of these analyses document that the current Rover hardware is not operable for any purpose, and any effort to restart this hardware will require extensive modifications and re-evaluation. However, various aspects of the Rover technology, such as the successful fluid-bed burner design, can be applied with modification to FSV fuel processing. The current regulatory climate and technical knowledge are not adequately defined to allow a complete analysis and conclusion with respect to the disposal of intact fuel blocks with or without the fuel rods removed. The primary unknowns include the various aspects of fuel-rod removal from the block, concentration of radionuclides remaining in the graphite block after rod removal, and acceptability of carbon in the form of graphite in a high level waste repository.

  7. The performative pleasure of imprecision: a diachronic study of entrainment in music performance.

    PubMed

    Geeves, Andrew; McIlwain, Doris J; Sutton, John

    2014-01-01

    This study focuses in on a moment of live performance in which the entrainment amongst a musical quartet is threatened. Entrainment is asymmetric in so far as there is an ensemble leader who improvises and expands the structure of a last chorus of a piece of music beyond the limits tacitly negotiated during prior rehearsals and performances. Despite the risk of entrainment being disturbed and performance interrupted, the other three musicians in the quartet follow the leading performer and smoothly transition into unprecedented performance territory. We use this moment of live performance to work back through the fieldwork data, building a diachronic study of the development and bases of entrainment in live music performance. We introduce the concept of entrainment and profile previous theory and research relevant to entrainment in music performance. After outlining our methodology, we trace the evolution of the structure of the piece of music from first rehearsal to final performance. Using video clip analysis, interviews and field notes we consider how entrainment shaped and was shaped by the moment of performance in focus. The sense of trust between quartet musicians is established through entrainment processes, is consolidated via smooth adaptation to the threats of disruption. Non-verbal communicative exchanges, via eye contact, gesture, and spatial proximity, sustain entrainment through phase shifts occurring swiftly and on the fly in performance contexts. These exchanges permit smooth adaptation promoting trust. This frees the quartet members to play with the potential disturbance of equilibrium inherent in entrained relationships and to play with this tension in an improvisatory way that enhances audience engagement and the live quality of performance. PMID:25400567

  8. The performative pleasure of imprecision: a diachronic study of entrainment in music performance

    PubMed Central

    Geeves, Andrew; McIlwain, Doris J.; Sutton, John

    2014-01-01

    This study focuses in on a moment of live performance in which the entrainment amongst a musical quartet is threatened. Entrainment is asymmetric in so far as there is an ensemble leader who improvises and expands the structure of a last chorus of a piece of music beyond the limits tacitly negotiated during prior rehearsals and performances. Despite the risk of entrainment being disturbed and performance interrupted, the other three musicians in the quartet follow the leading performer and smoothly transition into unprecedented performance territory. We use this moment of live performance to work back through the fieldwork data, building a diachronic study of the development and bases of entrainment in live music performance. We introduce the concept of entrainment and profile previous theory and research relevant to entrainment in music performance. After outlining our methodology, we trace the evolution of the structure of the piece of music from first rehearsal to final performance. Using video clip analysis, interviews and field notes we consider how entrainment shaped and was shaped by the moment of performance in focus. The sense of trust between quartet musicians is established through entrainment processes, is consolidated via smooth adaptation to the threats of disruption. Non-verbal communicative exchanges, via eye contact, gesture, and spatial proximity, sustain entrainment through phase shifts occurring swiftly and on the fly in performance contexts. These exchanges permit smooth adaptation promoting trust. This frees the quartet members to play with the potential disturbance of equilibrium inherent in entrained relationships and to play with this tension in an improvisatory way that enhances audience engagement and the live quality of performance. PMID:25400567

  9. Doing Duo – a case study of entrainment in William Forsythe’s choreography “Duo”

    PubMed Central

    Waterhouse, Elizabeth; Watts, Riley; Bläsing, Bettina E.

    2014-01-01

    Entrainment theory focuses on processes in which interacting (i.e., coupled) rhythmic systems stabilize, producing synchronization in the ideal sense, and forms of phase related rhythmic coordination in complex cases. In human action, entrainment involves spatiotemporal and social aspects, characterizing the meaningful activities of music, dance, and communication. How can the phenomenon of human entrainment be meaningfully studied in complex situations such as dance? We present an in-progress case study of entrainment in William Forsythe’s choreography Duo, a duet in which coordinated rhythmic activity is achieved without an external musical beat and without touch-based interaction. Using concepts of entrainment from different disciplines as well as insight from Duo performer Riley Watts, we question definitions of entrainment in the context of dance. The functions of chorusing, turn-taking, complementary action, cues, and alignments are discussed and linked to supporting annotated video material. While Duo challenges the definition of entrainment in dance as coordinated response to an external musical or rhythmic signal, it supports the definition of entrainment as coordinated interplay of motion and sound production by active agents (i.e., dancers) in the field. Agreeing that human entrainment should be studied on multiple levels, we suggest that entrainment between the dancers in Duo is elastic in time and propose how to test this hypothesis empirically. We do not claim that our proposed model of elasticity is applicable to all forms of human entrainment nor to all examples of entrainment in dance. Rather, we suggest studying higher order phase correction (the stabilizing tendency of entrainment) as a potential aspect to be incorporated into other models. PMID:25374522

  10. Plate-Based Fuel Processing System Final Report

    SciTech Connect

    Carlos Faz; Helen Liu; Jacques Nicole; David Yee

    2005-12-22

    On-board reforming of liquid fuels into hydrogen is an enabling technology that could accelerate consumer usage of fuel cell powered vehicles. The technology would leverage the convenience of the existing gasoline fueling infrastructure while taking advantage of the fuel cell efficiency and low emissions. Commercial acceptance of on-board reforming faces several obstacles that include: (1) startup time, (2) transient response, and (3) system complexity (size, weight and cost). These obstacles are being addressed in a variety of projects through development, integration and optimization of existing fuel processing system designs. In this project, CESI investigated steam reforming (SR), water-gas-shift (WGS) and preferential oxidation (PrOx) catalysts while developing plate reactor designs and hardware where the catalytic function is integrated into a primary surface heat exchanger. The plate reactor approach has several advantages. The separation of the reforming and combustion streams permits the reforming reaction to be conducted at a higher pressure than the combustion reaction, thereby avoiding costly gas compression for combustion. The separation of the two streams also prevents the dilution of the reformate stream by the combustion air. The advantages of the plate reactor are not limited to steam reforming applications. In a WGS or PrOx reaction, the non-catalytic side of the plate would act as a heat exchanger to remove the heat generated by the exothermic WGS or PrOx reactions. This would maintain the catalyst under nearly isothermal conditions whereby the catalyst would operate at its optimal temperature. Furthermore, the plate design approach results in a low pressure drop, rapid transient capable and attrition-resistant reactor. These qualities are valued in any application, be it on-board or stationary fuel processing, since they reduce parasitic losses, increase over-all system efficiency and help perpetuate catalyst durability. In this program, CESI

  11. Fuel quality/processing study. Volume 2: Appendix. Task 1 literature survey

    NASA Technical Reports Server (NTRS)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Klumpe, H. W.; Kessler, H. E.; Kotzot, H. T.; Loran, B. L.

    1981-01-01

    The results of a literature survey of fuel processing and fuel quality are given. Liquid synfuels produced from coal and oil shale are discussed. Gas turbine fuel property specifications are discussed. On-site fuel pretreatment and emissions from stationary gas turbines are discussed. Numerous data tables and abstracts are given.

  12. Conversion of microalgae to jet fuel: process design and simulation.

    PubMed

    Wang, Hui-Yuan; Bluck, David; Van Wie, Bernard J

    2014-09-01

    Microalgae's aquatic, non-edible, highly genetically modifiable nature and fast growth rate are considered ideal for biomass conversion to liquid fuels providing promise for future shortages in fossil fuels and for reducing greenhouse gas and pollutant emissions from combustion. We demonstrate adaptability of PRO/II software by simulating a microalgae photo-bio-reactor and thermolysis with fixed conversion isothermal reactors adding a heat exchanger for thermolysis. We model a cooling tower and gas floatation with zero-duty flash drums adding solids removal for floatation. Properties data are from PRO/II's thermodynamic data manager. Hydrotreating is analyzed within PRO/II's case study option, made subject to Jet B fuel constraints, and we determine an optimal 6.8% bioleum bypass ratio, 230°C hydrotreater temperature, and 20:1 bottoms to overhead distillation ratio. Process economic feasibility occurs if cheap CO2, H2O and nutrient resources are available, along with solar energy and energy from byproduct combustion, and hydrotreater H2 from product reforming. PMID:24997379

  13. Microbial fuel cell treatment of ethanol fermentation process water

    SciTech Connect

    Borole, Abhijeet P.

    2012-06-05

    The present invention relates to a method for removing inhibitor compounds from a cellulosic biomass-to-ethanol process which includes a pretreatment step of raw cellulosic biomass material and the production of fermentation process water after production and removal of ethanol from a fermentation step, the method comprising contacting said fermentation process water with an anode of a microbial fuel cell, said anode containing microbes thereon which oxidatively degrade one or more of said inhibitor compounds while producing electrical energy or hydrogen from said oxidative degradation, and wherein said anode is in electrical communication with a cathode, and a porous material (such as a porous or cation-permeable membrane) separates said anode and cathode.

  14. Thermal measurements and computational simulations of three-phase (CeO2-MgAl2O4-CeMgAl11O19) and four-phase (3Y-TZP-Al2O3-MgAl2O4-LaPO4) composites as surrogate inert matrix nuclear fuel

    NASA Astrophysics Data System (ADS)

    Angle, Jesse P.; Nelson, Andrew T.; Men, Danju; Mecartney, Martha L.

    2014-11-01

    This study investigates the temperature dependent thermal conductivity of multiphase ceramic composites for simulated inert matrix nuclear fuel. Fine grained composites were made of CeO2-MgAl2O4-CeMgAl11O19 or 3Y-TZP-Al2O3-MgAl2O4-LaPO4. CeO2 and 3Y-TZP are used as UO2 surrogates due to their similar structures and low thermal conductivities. Laser flash analysis from room temperature to 1273 K (1000 °C) was used to determine the temperature dependent thermal conductivity. A computational approach using Object Oriented Finite Element Analysis Version 2 (OOF2) was employed to simulate the composite thermal conductivity based on the microstructure. Observed discrepancies between experimental and simulated thermal conductivities at low temperature may be due to Kapitza resistance; however, there is less than 3% deviation between models and experiments above 673 K (400 °C) for both compositions. When the surrogate phase was replaced with UO2 in the computational model for the four-phase composite, a 12-16% increase in thermal conductivity resulted compared to single phase UO2, in the range of 673-1273 K (400-1000 °C). This computational approach may be potentially viable for the high-throughput evaluation of composite systems and the strategic selection of inert phases without extensive sample fabrication during the initial development stages of composite nuclear fuel design.

  15. PROCESS OF MAKING SHAPED FUEL FOR NUCLEAR REACTORS

    DOEpatents

    O'Leary, W.J.; Fisher, E.A.

    1964-02-11

    A process for making uranium dioxide fuel of great strength, density, and thermal conductivity by mixing it with 0.1 to 1% of a densifier oxide (tin, aluminum, zirconium, ferric, zinc, chromium, molybdenum, titanium, or niobium oxide) and with a plasticizer (0.5 to 3% of bentonite and 0.05 to 2% of methylcellulose, propylene glycol alginate, or ammonium alginate), compacting the mixture obtained, and sintering the bodies in an atmosphere of carbon monoxide or carbon dioxide, with or without hydrogen, or of a nitrogen-hydrogen mixture is described. (AEC)

  16. PROCESS OF MAKING A NEUTRONIC REACTOR FUEL ELEMENT COMPOSITION

    DOEpatents

    Alter, H.W.; Davidson, J.K.; Miller, R.S.; Mewherter, J.L.

    1959-01-13

    A process is presented for making a ceramic-like material suitable for use as a nuclear fuel. The material consists of a solid solution of plutonium dioxide in uranium dioxide and is produced from a uranyl nitrate -plutonium nitrate solution containing uraniunm and plutonium in the desired ratio. The uranium and plutonium are first precipitated from the solution by addition of NH/ sub 4/OH and the dried precipitate is then calcined at 600 C in a hydrogen atmosphere to yield the desired solid solution of PuO/sub 2/ in UO/sub 2/.

  17. Automated catalyst processing for cloud electrode fabrication for fuel cells

    DOEpatents

    Goller, Glen J.; Breault, Richard D.

    1980-01-01

    A process for making dry carbon/polytetrafluoroethylene floc material, particularly useful in the manufacture of fuel cell electrodes, comprises of the steps of floccing a co-suspension of carbon particles and polytetrafluoroethylene particles, filtering excess liquids from the co-suspension, molding pellet shapes from the remaining wet floc solids without using significant pressure during the molding, drying the wet floc pellet shapes within the mold at temperatures no greater than about 150.degree. F., and removing the dry pellets from the mold.

  18. Process for recovery of palladium from nuclear fuel reprocessing wastes

    DOEpatents

    Campbell, David O.; Buxton, Samuel R.

    1981-01-01

    Palladium is selectively removed from spent nuclear fuel reprocessing waste by adding sugar to a strong nitric acid solution of the waste to partially denitrate the solution and cause formation of an insoluble palladium compound. The process includes the steps of: (a) adjusting the nitric acid content of the starting solution to about 10 M, (b) adding 50% sucrose solution in an amount sufficient to effect the precipitation of the palladium compound, (c) heating the solution at reflux temperature until precipitation is complete, and (d) centrifuging the solution to separate the precipitated palladium compound from the supernatant liquid.

  19. Process for recovery of palladium from nuclear fuel reprocessing wastes

    DOEpatents

    Campbell, D.O.; Buxton, S.R.

    1980-06-16

    Palladium is selectively removed from spent nuclear fuel reprocessing waste by adding sugar to a strong nitric acid solution of the waste to partially denitrate the solution and cause formation of an insoluble palladium compound. The process includes the steps of: (a) adjusting the nitric acid content of the starting solution to about 10 M; (b) adding 50% sucrose solution in an amount sufficient to effect the precipitation of the palladium compound; (c) heating the solution at reflux temperature until precipitation is complete; and (d) centrifuging the solution to separate the precipitated palladium compound from the supernatant liquid.

  20. Temperature compensation and entrainment in circadian rhythms

    NASA Astrophysics Data System (ADS)

    Bodenstein, C.; Heiland, I.; Schuster, S.

    2012-06-01

    To anticipate daily variations in the environment and coordinate biological activities into a daily cycle many organisms possess a circadian clock. In the absence of external time cues the circadian rhythm persists with a period of approximately 24 h. The clock phase can be shifted by single pulses of light, darkness, chemicals, or temperature and this allows entrainment of the clock to exactly 24 h by cycles of these zeitgebers. On the other hand, the period of the circadian rhythm is kept relatively constant within a physiological range of constant temperatures, which means that the oscillator is temperature compensated. The mechanisms behind temperature compensation and temperature entrainment are not fully understood, neither biochemically nor mathematically. Here, we theoretically investigate the interplay of temperature compensation and entrainment in general oscillatory systems. We first give an analytical treatment for small temperature shifts and derive that every temperature-compensated oscillator is entrainable to external small-amplitude temperature cycles. Temperature compensation ensures that this entrainment region is always centered at the endogenous period regardless of possible seasonal temperature differences. Moreover, for small temperature cycles the entrainment region of the oscillator is potentially larger for rectangular pulses. For large temperature shifts we numerically analyze different circadian clock models proposed in the literature with respect to these properties. We observe that for such large temperature shifts sinusoidal or gradual temperature cycles allow a larger entrainment region than rectangular cycles.

  1. Entrained neural oscillations in multiple frequency bands comodulate behavior

    PubMed Central

    Henry, Molly J.; Herrmann, Björn

    2014-01-01

    Our sensory environment is teeming with complex rhythmic structure, to which neural oscillations can become synchronized. Neural synchronization to environmental rhythms (entrainment) is hypothesized to shape human perception, as rhythmic structure acts to temporally organize cortical excitability. In the current human electroencephalography study, we investigated how behavior is influenced by neural oscillatory dynamics when the rhythmic fluctuations in the sensory environment take on a naturalistic degree of complexity. Listeners detected near-threshold gaps in auditory stimuli that were simultaneously modulated in frequency (frequency modulation, 3.1 Hz) and amplitude (amplitude modulation, 5.075 Hz); modulation rates and types were chosen to mimic the complex rhythmic structure of natural speech. Neural oscillations were entrained by both the frequency modulation and amplitude modulation in the stimulation. Critically, listeners’ target-detection accuracy depended on the specific phase–phase relationship between entrained neural oscillations in both the 3.1-Hz and 5.075-Hz frequency bands, with the best performance occurring when the respective troughs in both neural oscillations coincided. Neural-phase effects were specific to the frequency bands entrained by the rhythmic stimulation. Moreover, the degree of behavioral comodulation by neural phase in both frequency bands exceeded the degree of behavioral modulation by either frequency band alone. Our results elucidate how fluctuating excitability, within and across multiple entrained frequency bands, shapes the effective neural processing of environmental stimuli. More generally, the frequency-specific nature of behavioral comodulation effects suggests that environmental rhythms act to reduce the complexity of high-dimensional neural states. PMID:25267634

  2. Entrainment ranges of forced phase oscillators.

    PubMed

    Previte, Joseph P; Sheils, Natalie; Hoffman, Kathleen A; Kiemel, Tim; Tytell, Eric D

    2011-04-01

    In the vertebrate spinal cord, a neural circuit called the central pattern generator produces the basic locomotory rhythm. Short and long distance intersegmental connections serve to maintain coordination along the length of the body. As a way of examining the influence of such connections, we consider a model of a chain of coupled phase oscillators in which one oscillator receives a periodic forcing stimulus. For a certain range of forcing frequencies, the chain will match the stimulus frequency, a phenomenon called entrainment. Motivated by recent experiments in lampreys, we derive analytical expressions for the range of forcing frequencies that entrain the chain, and how that range depends on the forcing location. For short intersegmental connections, in which an oscillator is connected only to its nearest neighbors, we describe two ways in which entrainment is lost: internally, in which oscillators within the chain no longer oscillate at the same frequency; and externally, in which the the chain no longer has the same frequency as the forcing. By analyzing chains in which every oscillator is connected to every other oscillator (i.e., all-to-all connections), we show that the presence of connections with lengths greater than one do not necessarily change the entrainment ranges based on the nearest-neighbor model. We derive a criterion for the ratio of connection strengths under which the connections of length greater than one do not change the entrainment ranges produced in the nearest-neighbor model, provided entrainment is lost externally. However, when this criterion holds, the range of entrained frequencies is a monotonic function of forcing location, unlike experimental results, in which entrainment ranges are larger near the middle of the chain than at the ends. Numerically, we show that similar non-monotonic entrainment ranges are possible if the ratio criterion does not hold, suggesting that in the lamprey central pattern generator, intersegmental

  3. Modified mass action law-based model to correlate the solubility of solids and liquids in entrained supercritical carbon dioxide.

    PubMed

    González, J C; Vieytes, M R; Botana, A M; Vieites, J M; Botana, L M

    2001-02-23

    The solubility of solids and liquids in supercritical CO2 with added entrainers was modeled with a modified version of the equation of Chrastil to include the effect of entrainers. By considering the formation of the solute-entrainer-solvent complexes an equation is obtained which predicts an exponential increase of solubility with fluid density and/or entrainer concentration. The correlating model was tested by non-linear regression through a computerized iterative process for several systems where an entrainer was present. Four experimental parameters are easily regressed from experimental data, hence the corresponding properties of components such as chemical potentials or critical parameters are not needed. Instead of its simplicity, this thermodynamical model provided a good correlation of the solubility enhancement in the presence of entrainer effect. PMID:11263564

  4. Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system

    PubMed Central

    Thaut, Michael H.; McIntosh, Gerald C.; Hoemberg, Volker

    2015-01-01

    Entrainment is defined by a temporal locking process in which one system’s motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks) and biological systems (e.g., fire flies). However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al., 1999). Physiological, kinematic, and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of neurologic music therapy. PMID:25774137

  5. Neurobiological foundations of neurologic music therapy: rhythmic entrainment and the motor system.

    PubMed

    Thaut, Michael H; McIntosh, Gerald C; Hoemberg, Volker

    2014-01-01

    Entrainment is defined by a temporal locking process in which one system's motion or signal frequency entrains the frequency of another system. This process is a universal phenomenon that can be observed in physical (e.g., pendulum clocks) and biological systems (e.g., fire flies). However, entrainment can also be observed between human sensory and motor systems. The function of rhythmic entrainment in rehabilitative training and learning was established for the first time by Thaut and colleagues in several research studies in the early 1990s. It was shown that the inherent periodicity of auditory rhythmic patterns could entrain movement patterns in patients with movement disorders (see for a review: Thaut et al., 1999). Physiological, kinematic, and behavioral movement analysis showed very quickly that entrainment cues not only changed the timing of movement but also improved spatial and force parameters. Mathematical models have shown that anticipatory rhythmic templates as critical time constraints can result in the complete specification of the dynamics of a movement over the entire movement cycle, thereby optimizing motor planning and execution. Furthermore, temporal rhythmic entrainment has been successfully extended into applications in cognitive rehabilitation and speech and language rehabilitation, and thus become one of the major neurological mechanisms linking music and rhythm to brain rehabilitation. These findings provided a scientific basis for the development of neurologic music therapy. PMID:25774137

  6. Effect of firing temperature on the microstructure and performance of PrBaCo 2O 5+ δ cathodes on Sm 0.2Ce 0.8O 1.9 electrolytes fabricated by spray deposition-firing processes

    NASA Astrophysics Data System (ADS)

    Chen, Dengjie; Ran, Ran; Shao, Zongping

    The effect of firing temperature on the microstructure and performance of PrBaCo 2O 5+ δ cathodes on Sm 0.2Ce 0.8O 1.9 electrolytes fabricated by spray deposition-firing processes is systematically studied by various characterization techniques. The grain size, porosity and particle connection of the electrode as well as the physical contact between the PrBaCo 2O 5+ δ and Sm 0.2Ce 0.8O 1.9 layers are influenced differently by the firing temperature. The area specific resistances (ASRs) of the various PrBaCo 2O 5+ δ cathodes are measured by electrochemical impedance spectroscopy in both symmetrical two-electrode and three-electrode configurations. The lowest ASR and cathode overpotential are achieved at a firing temperature of 1000 °C. Two main oxygen reduction reaction processes are proposed according to the oxygen partial pressure dependence of the electrode ASR. The rate-determining step is transmitted from a charge-transfer process at low firing temperatures to a non-charge-transfer process at high firing temperatures. A fuel cell with the PrBaCo 2O 5+ δ cathode fired at an optimal temperature of 1000 °C delivers the attractive peak power density of 835 mW cm -2 at 650 °C, while this density is much lower for other firing temperatures. This result suggests the firing temperature of PrBaCo 2O 5+ δ electrodes should be carefully optimized for practical applications.

  7. Thermochemical Process Development Unit: Researching Fuels from Biomass, Bioenergy Technologies (Fact Sheet)

    SciTech Connect

    Not Available

    2009-01-01

    The Thermochemical Process Development Unit (TCPDU) at the National Renewable Energy Laboratory (NREL) is a unique facility dedicated to researching thermochemical processes to produce fuels from biomass.

  8. Low temperature co-sintering of Sr2Fe1.5Mo0.5O6-δ-Gd0.1Ce0.9O2-δ anode-supported solid oxide fuel cells with Li2O-Gd0.1Ce0.9O2-δ electrolyte

    NASA Astrophysics Data System (ADS)

    Yang, Zhibin; Yang, Yanru; Chen, Yu; Liu, Yahui; Zhu, Tenglong; Han, Minfang; Chen, Fanglin

    2015-11-01

    Sr2Fe1.5Mo0.5O6-δ-Gd0.1Ce0.9O1.95(SFM-GDC) ceramic anode-supported solid oxide fuel cell with GDC crack-free electrolyte film (∼80 μm) has been fabricated by co-pressing and co-sintering at temperature as low as 1150 °C for 5 h by introducing 2.5 mol% Li2O as sintering-aid. The peak power density of such cells with Ba0.9Co0.7Fe0.2Nb0.1O3-δ (BCFN) cathode can reach 200 mW cm-2 at 700 °C when using H2 as fuel and ambient air as oxidant. In addition, the anode shows an excellent sulfur tolerance when using H2 with 50 ppm H2S as fuel.

  9. NEW MATERIAL NEEDS FOR HYDROCARBON FUEL PROCESSING: Generating Hydrogen for the PEM Fuel Cell

    NASA Astrophysics Data System (ADS)

    Farrauto, R.; Hwang, S.; Shore, L.; Ruettinger, W.; Lampert, J.; Giroux, T.; Liu, Y.; Ilinich, O.

    2003-08-01

    The hydrogen economy is fast approaching as petroleum reserves are rapidly consumed. The fuel cell promises to deliver clean and efficient power by combining hydrogen and oxygen in a simple electrochemical device that directly converts chemical energy to electrical energy. Hydrogen, the most plentiful element available, can be extracted from water by electrolysis. One can imagine capturing energy from the sun and wind and/or from the depths of the earth to provide the necessary power for electrolysis. Alternative energy sources such as these are the promise for the future, but for now they are not feasible for power needs across the globe. A transitional solution is required to convert certain hydrocarbon fuels to hydrogen. These fuels must be available through existing infrastructures such as the natural gas pipeline. The present review discusses the catalyst and adsorbent technologies under development for the extraction of hydrogen from natural gas to meet the requirements for the proton exchange membrane (PEM) fuel cell. The primary market is for residential applications, where pipeline natural gas will be the source of H2 used to power the home. Other applications including the reforming of methanol for portable power applications such as laptop computers, cellular phones, and personnel digital equipment are also discussed. Processing natural gas containing sulfur requires many materials, for example, adsorbents for desulfurization, and heterogeneous catalysts for reforming (either autothermal or steam reforming) water gas shift, preferential oxidation of CO, and anode tail gas combustion. All these technologies are discussed for natural gas and to a limited extent for reforming methanol.

  10. Sintering Studies of Ga-Doped CeO{sub 2} (Ga-Doped PuO{sub 2} Surrogate) for Mixed Oxide Nuclear Fuel

    SciTech Connect

    Haertling, C.; Huling, J.; Park, Y.S.

    1999-04-25

    Sintering studies of CeO{sub 2} and CeO{sub 2} + 2 wt. % Ga{sub 2}O{sub 3} were completed. Firing temperatures studied were 1250-1650 C with 2 to 4 hour firing soak times in air. Powders fabricated by three methods (as-received, attrition-mill and nitrite-derived) were studied. Attrition-milled CeO{sub 2} improved densities as compared with as-received CeO{sub 2}. Attrition-milled CeO{sub 2} with 2 wt.% Ga{sub 2}O{sub 3} showed decreased densities with increasing temperatures. As-received CeO{sub 2} with 2 wt.% Ga{sub 2}O{sub 3} showed a opposite trend, increasing in density with increased firing temperature. Two pellet preparation methods were studied, a one-step-press method and a two-step-press method. The two-step-press method showed greater densities at lower firing temperatures and times as compared with the one-step-press method, however for CeO{sub 2} + 2 wt.% Ga{sub 2}O{sub 3}, the two methods gave equivalent results at 1650 C, 6 hr. firing conditions.

  11. Laboratory experiments on stability and entrainment of oceanic stratocumulus. Part 1: Instability experiment

    NASA Technical Reports Server (NTRS)

    Shy, Shenqyang S.

    1990-01-01

    The existence and persistence of marine stratocumulus play a significant role in the overall energy budget of the earth. Their stability and entrainment process are important in global climate studies, as well as for local weather forecasting. The purposes of the experimental simulations are to study this process and to address this paradox. The effects of buoyancy reversal is investigated, followed by two types of experiments. An instability experiment involves the behavior of a fully turbulent wake near the inversion generated by a sliding plate. Due to buoyancy reversal, the heavy, mixed fluid starts to sink, turning the potential energy created by the mixing process into kinetic energy, thereby increasing the entrainment rate. An entrainment experiment, using a vertically oscillating grid driven by a controllable speed motor, produces many eddy-induced entrainments at a surface region on scales much less than the depth of the layer.

  12. Maximizing the liquid fuel yield in a biorefining process.

    PubMed

    Zhang, Bo; von Keitz, Marc; Valentas, Kenneth

    2008-12-01

    Biorefining strives to recover the maximum value from each fraction, at minimum energy cost. In order to seek an unbiased and thorough assessment of the alleged opportunity offered by biomass fuels, the direct conversion of various lignocellulosic biomass was studied: aspen pulp wood (Populus tremuloides), aspen wood pretreated with dilute acid, aspen lignin, aspen logging residues, corn stalk, corn spathe, corn cob, corn stover, corn stover pellet, corn stover pretreated with dilute acid, and lignin extracted from corn stover. Besides the heating rate, the yield of liquid products was found to be dependent on the final liquefaction temperature and the length of liquefaction time. The major compounds of the liquid products from various origins were identified by GC-MS. The lignin was found to be a good candidate for the liquefaction process, and biomass fractionation was necessary to maximize the yield of the liquid bio-fuel. The results suggest a biorefinery process accompanying pretreatment, fermentation to ethanol, liquefaction to bio-crude oil, and other thermo-conversion technologies, such as gasification. Other biorefinery options, including supercritical water gasification and the effectual utilization of the bio-crude oil, are also addressed. PMID:18781691

  13. Synthesis of Diopside by Solution Combustion Process Using Glycine Fuel

    NASA Astrophysics Data System (ADS)

    Sherikar, Baburao N.; Umarji, A. M.

    Nano ceramic Diopside (CaMgSi2O6) powders are synthesized by Solution Combustion Process(SCS) using Calcium nitrate, Magnesium nitrate as oxidizer and glycine as fuel, fumed silica as silica source. Ammonium nitrate (AN) is used as extra oxidizer. Effect of AN on Diopside phase formation is investigated. The adiabatic flame temperatures are calculated theoretically for varying amount of AN according to thermodynamic concept and correlated with the observed flame temperatures. A “Multi channel thermocouple setup connected to computer interfaced Keithley multi voltmeter 2700” is used to monitor the thermal events during the process. An interpretation based on maximum combustion temperature and the amount of gases produced during reaction for various AN compositions has been proposed for the nature of combustion and its correlation with the characteristics of as synthesized powder. These powders are characterized by XRD, SEM showing that the powders are composed of polycrystalline oxides with crystallite size of 58nm to 74nm.

  14. Process for converting cellulosic materials into fuels and chemicals

    DOEpatents

    Scott, C.D.; Faison, B.D.; Davison, B.H.; Woodward, J.

    1994-09-20

    A process is described for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attrition mill and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system. 1 fig.

  15. Flow Dynamics and Sediment Entrainment in Natural Turbidity Currents Inferred from Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Traer, M. M.; Hilley, G. E.; Fildani, A.

    2009-12-01

    Submarine turbidity currents derive their momentum from gravity acting upon the density contrast between sediment-laden and clear water, and so unlike fluvial systems, the dynamics of such flows are inextricably linked to the rates at which they deposit and entrain sediment. We have analyzed the sensitivity of the growth and maintenance of turbidity currents to sediment entrainment and deposition using the layer-averaged equations of conservation of fluid and sediment mass, and conservation of momentum and turbulent kinetic energy. Our model results show that the dynamics of turbidity currents are extremely sensitive to the functional form and empirical constants of the relationship between sediment entrainment and friction velocity. Data on the relationship between sediment entrainment and friction velocity for submarine density flows are few and as a result, entrainment formulations are populated with data from sub-aerial flows not driven by the density contrast between clear and turbid water. If we entertain the possibility that sediment entrainment in sub-aerial rivers is different than in dense underflows, flow parameters such as velocity, height, and concentration were found nearly impossible to predict beyond a few hundred meters based on the limited laboratory data available that constrain the sediment entrainment process in turbidity currents. The sensitivity of flow dynamics to the functional relationship between friction velocity and sediment entrainment indicates that independent calibration of a sediment entrainment law in the submarine environment is necessary to realistically predict the dynamics of these flows and the resulting patterns of erosion and deposition. To calibrate such a relationship, we have developed an inverse methodology that utilizes existing submarine channel morphology as a means of constraining the sediment entrainment function parameters. We use a Bayesian Metropolis-Hastings sampler to determine the sediment entrainment

  16. Decommissioning the Fuel Process Building, a Shift in Paradigm for Terminating Safeguards on Process Holdup

    SciTech Connect

    Ivan R. Thomas

    2010-07-01

    INMM Abstract 51st Annual Meeting Decommissioning the Fuel Process Building, a Shift in Paradigm for Terminating Safeguards on Process Holdup The Fuel Process Building at the Idaho Nuclear Technology and Engineering Center (INTEC) is being decommissioned after nearly four decades of recovering high enriched uranium from various government owned spent nuclear fuels. The separations process began with fuel dissolution in one of multiple head-ends, followed by three cycles of uranium solvent extraction, and ending with denitration of uranyl nitrate product. The entire process was very complex, and the associated equipment formed an extensive maze of vessels, pumps, piping, and instrumentation within several layers of operating corridors and process cells. Despite formal flushing and cleanout procedures, an accurate accounting for the residual uranium held up in process equipment over extended years of operation, presented a daunting safeguards challenge. Upon cessation of domestic reprocessing, the holdup remained inaccessible and was exempt from measurement during ensuing physical inventories. In decommissioning the Fuel Process Building, the Idaho Cleanup Project, which operates the INTEC, deviated from the established requirements that all nuclear material holdup be measured and credited to the accountability books and that all nuclear materials, except attractiveness level E residual holdup, be transferred to another facility. Instead, the decommissioning involved grouting the process equipment in place, rather than measuring and removing the contained holdup for subsequent transfer. The grouting made the potentially attractiveness level C and D holdup even more inaccessible, thereby effectually converting the holdup to attractiveness level E and allowing for termination of safeguards controls. Prior to grouting the facility, the residual holdup was estimated by limited sampling and destructive analysis of solutions in process lines and by acceptable knowledge

  17. I. Mixing in doorway flows. II. Entrainment in fire plumes

    NASA Astrophysics Data System (ADS)

    Lim, Christopher S.

    entrainment measurements are obtained from a chemical analysis of a dried sample of combustion products taken from the ceiling layer. The measured species concentrations are compared with the theoretical equilibrium composition of the ceiling layer gas. For a given interface height, the ceiling layer gas temperature is found to be a linear function of the fuel-air ratio up to the stoichiometric fuel-air ratio. Increasing the fuel-air ratio above the stoichiometric value did not change the gas temperature significantly. This maximum temperature is observed to decrease with interface height. The air entrainment rates are found to be a weak function of the fuel-air ratio at very low elevations of the interface.

  18. Review of solar fuel-producing quantum conversion processes

    NASA Astrophysics Data System (ADS)

    Peterson, D. B.; Biddle, J. R.; Fujita, T.

    1984-05-01

    The status and potential of fuel-producing solar photochemical processes are discussed. Research focused on splitting water to produce dihydrogen and is at a relatively early stage of development. Current emphasis is primarily directed toward understanding the basic chemistry underlying such quantum conversion processes. Theoretical analyses by various investigators predict a limiting thermodynamic efficiency of 31% for devices with a single photosystem operating with unfocused sunlight at 300 K. When non-idealities are included, it appears unlikely that actual devices will have efficiencies greater than 12 to 15%. Observed efficiencies are well below theoretical limits. Cyclic homogeneous photochemical processes for splitting water have efficiencies considerably less than 1%. Efficiency can be significantly increased by addition of a sacrificial reagent; however, such systems are no longer cyclic and it is doubtful that they would be economical on a commercial scale. The observed efficiencies for photoelectrochemical processes are also low but such systems appear more promising than homogeneous photochemical systems. Operating and systems options, including operation at elevated temperature and hybrid and coupled quantum-thermal conversion processes, are also considered.

  19. Review of solar fuel-producing quantum conversion processes

    NASA Technical Reports Server (NTRS)

    Peterson, D. B.; Biddle, J. R.; Fujita, T.

    1984-01-01

    The status and potential of fuel-producing solar photochemical processes are discussed. Research focused on splitting water to produce dihydrogen and is at a relatively early stage of development. Current emphasis is primarily directed toward understanding the basic chemistry underlying such quantum conversion processes. Theoretical analyses by various investigators predict a limiting thermodynamic efficiency of 31% for devices with a single photosystem operating with unfocused sunlight at 300 K. When non-idealities are included, it appears unlikely that actual devices will have efficiencies greater than 12 to 15%. Observed efficiencies are well below theoretical limits. Cyclic homogeneous photochemical processes for splitting water have efficiencies considerably less than 1%. Efficiency can be significantly increased by addition of a sacrificial reagent; however, such systems are no longer cyclic and it is doubtful that they would be economical on a commercial scale. The observed efficiencies for photoelectrochemical processes are also low but such systems appear more promising than homogeneous photochemical systems. Operating and systems options, including operation at elevated temperature and hybrid and coupled quantum-thermal conversion processes, are also considered.

  20. Washing of the AN-107 entrained solids

    SciTech Connect

    GJ Lumetta; FV Hoopes

    2000-03-31

    This report describes the results of a test conducted by Battelle to assess the effects of inhibited water washing on the composition of the entrained solids in the diluted AN-107 low-activity waste (LAW) sample. The objective of this work was to gather data on the solubility of the AN-107 entrained solids in 0.01 M NaOH, so that BNFL can evaluate whether these solids require caustic leaching.

  1. Informational Constraints on Spontaneous Visuomotor Entrainment

    PubMed Central

    Varlet, Manuel; Bucci, Colleen; Richardson, Michael J.; Schmidt, R. C.

    2015-01-01

    Past research has revealed that an individual's rhythmic limb movements become spontaneously entrained to an environmental rhythm if visual information about the rhythm is available and its frequency is near that of the individual's movements. Research has also demonstrated that if the eyes track an environmental stimulus, the spontaneous entrainment to the rhythm is strengthened. One hypothesis explaining this enhancement of spontaneous entrainment is that the limb movements and eye movements are linked through a neuromuscular coupling or synergy. Another is that eye-tracking facilitates the pick up of important coordinating information. Experiment 1 investigated the first hypothesis by evaluating whether any rhythmic movement of the eyes would facilitate spontaneous entrainment. Experiment 2 and 3 (respectively) explored whether eye-tracking strengthens spontaneous entrainment by allowing the pickup of trajectory direction change information or allowing an increase in the amount of information to be picked-up. Results suggest that the eye-tracking enhancement of spontaneous entrainment is a consequence of increasing the amount of information available to be picked-up. PMID:25866944

  2. Coupling governs entrainment range of circadian clocks

    PubMed Central

    Abraham, Ute; Granada, Adrián E; Westermark, Pål O; Heine, Markus; Kramer, Achim; Herzel, Hanspeter

    2010-01-01

    Circadian clocks are endogenous oscillators driving daily rhythms in physiology and behavior. Synchronization of these timers to environmental light–dark cycles (‘entrainment') is crucial for an organism's fitness. Little is known about which oscillator qualities determine entrainment, i.e., entrainment range, phase and amplitude. In a systematic theoretical and experimental study, we uncovered these qualities for circadian oscillators in the suprachiasmatic nucleus (SCN—the master clock in mammals) and the lung (a peripheral clock): (i) the ratio between stimulus (zeitgeber) strength and oscillator amplitude and (ii) the rigidity of the oscillatory system (relaxation rate upon perturbation) determine entrainment properties. Coupling among oscillators affects both qualities resulting in increased amplitude and rigidity. These principles explain our experimental findings that lung clocks entrain to extreme zeitgeber cycles, whereas SCN clocks do not. We confirmed our theoretical predictions by showing that pharmacological inhibition of coupling in the SCN leads to larger ranges of entrainment. These differences between master and the peripheral clocks suggest that coupling-induced rigidity in the SCN filters environmental noise to create a robust circadian system. PMID:21119632

  3. Tuning the phase of circadian entrainment

    PubMed Central

    Bordyugov, Grigory; Abraham, Ute; Granada, Adrian; Rose, Pia; Imkeller, Katharina; Kramer, Achim; Herzel, Hanspeter

    2015-01-01

    The circadian clock coordinates daily physiological, metabolic and behavioural rhythms. These endogenous oscillations are synchronized with external cues (‘zeitgebers’), such as daily light and temperature cycles. When the circadian clock is entrained by a zeitgeber, the phase difference ψ between the phase of a clock-controlled rhythm and the phase of the zeitgeber is of fundamental importance for the fitness of the organism. The phase of entrainment ψ depends on the mismatch between the intrinsic period τ and the zeitgeber period T and on the ratio of the zeitgeber strength to oscillator amplitude. Motivated by the intriguing complexity of empirical data and by our own experiments on temperature entrainment of mouse suprachiasmatic nucleus (SCN) slices, we present a theory on how clock and zeitgeber properties determine the phase of entrainment. The wide applicability of the theory is demonstrated using mathematical models of different complexity as well as by experimental data. Predictions of the theory are confirmed by published data on Neurospora crassa strains for different period mismatches τ − T and varying photoperiods. We apply a novel regression technique to analyse entrainment of SCN slices by temperature cycles. We find that mathematical models can explain not only the stable asymptotic phase of entrainment, but also transient phase dynamics. Our theory provides the potential to explore seasonal variations of circadian rhythms, jet lag and shift work in forthcoming studies. PMID:26136227

  4. Tuning the phase of circadian entrainment.

    PubMed

    Bordyugov, Grigory; Abraham, Ute; Granada, Adrian; Rose, Pia; Imkeller, Katharina; Kramer, Achim; Herzel, Hanspeter

    2015-07-01

    The circadian clock coordinates daily physiological, metabolic and behavioural rhythms. These endogenous oscillations are synchronized with external cues ('zeitgebers'), such as daily light and temperature cycles. When the circadian clock is entrained by a zeitgeber, the phase difference ψ between the phase of a clock-controlled rhythm and the phase of the zeitgeber is of fundamental importance for the fitness of the organism. The phase of entrainment ψ depends on the mismatch between the intrinsic period τ and the zeitgeber period T and on the ratio of the zeitgeber strength to oscillator amplitude. Motivated by the intriguing complexity of empirical data and by our own experiments on temperature entrainment of mouse suprachiasmatic nucleus (SCN) slices, we present a theory on how clock and zeitgeber properties determine the phase of entrainment. The wide applicability of the theory is demonstrated using mathematical models of different complexity as well as by experimental data. Predictions of the theory are confirmed by published data on Neurospora crassa strains for different period mismatches τ - T and varying photoperiods. We apply a novel regression technique to analyse entrainment of SCN slices by temperature cycles. We find that mathematical models can explain not only the stable asymptotic phase of entrainment, but also transient phase dynamics. Our theory provides the potential to explore seasonal variations of circadian rhythms, jet lag and shift work in forthcoming studies. PMID:26136227

  5. Optimized CeO2 content of the carbon nanofiber support of PtRu catalyst for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Kunitomo, Hikari; Ishitobi, Hirokazu; Nakagawa, Nobuyoshi

    2015-11-01

    A series of CeO2 embedded carbon nanofibers, CECNFs, with different CeO2 contents was prepared by an electrospinning technique. About 15 wt% PtRu nanoparticles were deposited on the fibers, and the effect of the CeO2 content on the methanol oxidation activity of the catalyst, PtRu/CECNF, was investigated. Cyclic voltammetry (CV), chronoamperometry (CA) and CO stripping electrochemical measurements and physical characterization along with X-ray diffraction (XRD) analysis, energy dispersive X-ray (EDX) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were carried out on the prepared catalysts. The mass activity of the PtRu was significantly increased by the CeO2 addition up to Ce/C = 0.4, and the maximized activity was 2 times higher than that without CeO2. The increased activity was attributed to the strong interaction between the metal and oxide in the embedded nanofiber structure. A DMFC with the PtRu/CECNF exhibited more than 2.5 times high power density with one half the PtRu loading compared to that of the commercial catalyst, PtRu/Ccom.

  6. Music and emotions: from enchantment to entrainment.

    PubMed

    Vuilleumier, Patrik; Trost, Wiebke

    2015-03-01

    Producing and perceiving music engage a wide range of sensorimotor, cognitive, and emotional processes. Emotions are a central feature of the enjoyment of music, with a large variety of affective states consistently reported by people while listening to music. However, besides joy or sadness, music often elicits feelings of wonder, nostalgia, or tenderness, which do not correspond to emotion categories typically studied in neuroscience and whose neural substrates remain largely unknown. Here we review the similarities and differences in the neural substrates underlying these "complex" music-evoked emotions relative to other more "basic" emotional experiences. We suggest that these emotions emerge through a combination of activation in emotional and motivational brain systems (e.g., including reward pathways) that confer its valence to music, with activation in several other areas outside emotional systems, including motor, attention, or memory-related regions. We then discuss the neural substrates underlying the entrainment of cognitive and motor processes by music and their relation to affective experience. These effects have important implications for the potential therapeutic use of music in neurological or psychiatric diseases, particularly those associated with motor, attention, or affective disturbances. PMID:25773637

  7. Environmental assessment for radioisotope heat source fuel processing and fabrication

    SciTech Connect

    Not Available

    1991-07-01

    DOE has prepared an Environmental Assessment (EA) for radioisotope heat source fuel processing and fabrication involving existing facilities at the Savannah River Site (SRS) near Aiken, South Carolina and the Los Alamos National Laboratory (LANL) near Los Alamos, New Mexico. The proposed action is needed to provide Radioisotope Thermoelectric Generators (RTG) to support the National Aeronautics and Space Administration's (NASA) CRAF and Cassini Missions. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement is not required. 30 refs., 5 figs.

  8. Sulfur tolerant molten carbonate fuel cell anode and process

    DOEpatents

    Remick, Robert J.

    1990-01-01

    Molten carbonate fuel cell anodes incorporating a sulfur tolerant carbon monoxide to hydrogen water-gas-shift catalyst provide in situ conversion of carbon monoxide to hydrogen for improved fuel cell operation using fuel gas mixtures of over about 10 volume percent carbon monoxide and up to about 10 ppm hydrogen sulfide.

  9. Thermodynamic analysis and comparison on oxy-fuel power generation process - article no. 053001

    SciTech Connect

    Deng, S.M.; Hynes, R.

    2009-09-15

    In this paper, pressurized oxy-fuel combustion power generation processes are modeled and analyzed based on a 350 MW subcritical reheat boiler associated with a condensing steam turbine. The performance results are obtained. Furthermore, the influences of slurry concentration and coal properties on power plant performance are investigated. An oxy-fuel configuration operating at ambient pressure is studied to compare the performance with pressurized oxy-fuel configuration. Thermodynamic analysis reveals the true potentials of the pressurized oxy-fuel process. Based on the system integration, an improved configuration is proposed in which plant efficiency of pressurized oxy-fuel process is increased by 1.36%.

  10. IMPROVED LABORATORY TRANSITION PROBABILITIES FOR Ce II, APPLICATION TO THE CERIUM ABUNDANCES OF THE SUN AND FIVE r-PROCESS-RICH, METAL-POOR STARS, AND RARE EARTH LAB DATA SUMMARY

    SciTech Connect

    Lawler, J. E.; Den Hartog, E. A.; Sneden, C.; Cowan, J. J.; Ivans, I. I. E-mail: eadenhar@wisc.edu E-mail: cowan@nhn.ou.edu

    2009-05-15

    Recent radiative lifetime measurements accurate to {+-}5% using laser-induced fluorescence (LIF) on 43 even-parity and 15 odd-parity levels of Ce II have been combined with new branching fractions measured using a Fourier transform spectrometer (FTS) to determine transition probabilities for 921 lines of Ce II. This improved laboratory data set has been used to determine a new solar photospheric Ce abundance, log {epsilon} = 1.61 {+-} 0.01 ({sigma} = 0.06 from 45 lines), a value in excellent agreement with the recommended meteoritic abundance, log {epsilon} = 1.61 {+-} 0.02. Revised Ce abundances have also been derived for the r-process-rich metal-poor giant stars BD+17{sup 0}3248, CS 22892-052, CS 31082-001, HD 115444, and HD 221170. Between 26 and 40 lines were used for determining the Ce abundance in these five stars, yielding a small statistical uncertainty of {+-}0.01 dex similar to the solar result. The relative abundances in the metal-poor stars of Ce and Eu, a nearly pure r-process element in the Sun, matches r-process-only model predictions for solar system material. This consistent match with small scatter over a wide range of stellar metallicities lends support to these predictions of elemental fractions. A companion paper includes an interpretation of these new precision abundance results for Ce as well as new abundance results and interpretation for Pr, Dy, and Tm.

  11. The effect of low-NO{sub x} combustion on residual carbon in fly ash and its adsorption capacity for air entrainment admixtures in concrete

    SciTech Connect

    Pedersen, K.H.; Jensen, A.D.; Dam-Johansen, K.

    2010-02-15

    Fly ash from pulverized coal combustion contains residual carbon that can adsorb the air-entraining admixtures (AEAs) added to control the air entrainment in concrete. This is a problem that has increased by the implementation of low-NO{sub x} combustion technologies. In this work, pulverized fuel has been combusted in an entrained flow reactor to test the impact of changes in operating conditions and fuel type on the AEA adsorption of ash and NO{sub x} formation. Increased oxidizing conditions, obtained by improved fuel-air mixing or higher excess air, decreased the AEA requirements of the produced ash by up to a factor of 25. This was due to a lower carbon content in the ash and a lower specific AEA adsorptivity of the carbon. The latter was suggested to be caused by changes in the adsorption properties of the unburned char and a decreased formation of soot, which was found to have a large AEA adsorption capacity based on measurements on a carbon black. The NO{sub x} formation increased by up to three times with more oxidizing conditions and thus, there was a trade-off between the AEA requirements of the ash and NO{sub x} formation. The type of fuel had high impact on the AEA adsorption behavior of the ash. Ashes produced from a Columbian and a Polish coal showed similar AEA requirements, but the specific AEA adsorptivity of the carbon in the Columbian coal ash was up to six times higher. The AEA requirements of a South African coal ash was unaffected by the applied operating conditions and showed up to 12 times higher AEA adsorption compared to the two other coal ashes. This may be caused by larger particles formed by agglomeration of the primary coal particles in the feeding phase or during the combustion process, which gave rise to increased formation of soot. (author)

  12. Integrated microchemical systems for fuel processing in micro fuel cell applications

    NASA Astrophysics Data System (ADS)

    Pattekar, Ashish V.

    Rapid advances in microelectronics technology over the last decade have led to the search for novel applications of miniaturization to all aspects of engineering. Microreaction engineering, which involves the development of miniature reactors on microchips for novel applications, has been a key area of interest in this quest for miniaturization. The idea of a fully integrated microplant with embedded control electronics, sensors and actuators on a single silicon chip has been gaining increasing acceptance as significant progress is being made in this area. The aim of this project has been to demonstrate a working microreaction system for hydrogen delivery to miniature proton exchange membrane (PEM) fuel cells through the catalytic steam reforming of methanol. The complete reformer - fuel cell unit is proposed as an alternative to conventional portable sources of electricity such as batteries due to its ability to provide an uninterrupted supply of electricity as long as a supply of methanol and water can be provided. This technology also offers significantly higher energy storage densities, which translates into less frequent 'recharging' through the refilling of methanol fuel. Various aspects of the design of a miniature methanol reformer on a silicon substrate are discussed with a focus on the theoretical understanding of microreactor operation and optimum utilization of the semiconductor-processing techniques used for fabricating the devices. Three prototype microreactor designs have been successfully fabricated and tested. Issues related to microchannel capping, on-chip heating and temperature sensing, introduction and trapping of catalyst particles in microchannels, microfluidic interfacing, pressure drop reduction, and thermal insulation have been addressed. Details regarding modeling and simulation of the designs to provide an insight into the working of the microreactor are presented along with a description of the microfabrication steps followed to

  13. Assessment of sulfur removal processes for advanced fuel cell systems

    SciTech Connect

    Lorton, G.A.

    1980-01-01

    This study consisted of a technical evaluation and economic comparison of sulfur removal processes for integration into a coal gasification-molten carbonate (CGMC) fuel cell power plant. Initially, the performance characteristics of potential sulfur removal processes were evaluated and screened for conformance to the conditions and requirements expected in commercial CGMC power plants. Four of these processes, the Selexol process, the Benfield process, the Sulfinol process, and the Rectisol process, were selected for detailed technical and economic comparison. The process designs were based on a consistent set of technical criteria for a grass roots facility with a capacity of 10,000 tons per day of Illinois No. 6 coal. Two raw gas compositions, based on oxygen-blown and air-blown Texaco gasification, were used. The bulk of the sulfur was removed in the sulfur removal unit, leaving a small amount of sulfur compounds in the gas (1 ppMv or 25 ppMv). The remaining sulfur compounds were removed by reaction with zinc oxide in the sulfur polishing unit. The impact of COS hydrolysis pretreatment on sulfur removal was evaluated. Comprehensive capital and O and M cost estimates for each of the process schemes were developed for the essentially complete removal of sulfur compounds. The impact on the overall plant performance was also determined. The total capital requirement for sulfur removal schemes ranged from $59.4/kW to $84.8/kW for the oxygen-blown cases and from $89.5/kW to $133/kW for the air-blown cases. The O and M costs for sulfur removal for 70% plant capacity factor ranged from 0.82 mills/kWh to 2.76 mills/kWh for the oxygen-blown cases and from 1.77 mills/kWh to 4.88 mills/kWh for the air-blown cases. The Selexol process benefitted the most from the addition of COS hydrolysis pretreatment.

  14. Laboratory experiments investigating entrainment by debris flows and associated increased mobility

    NASA Astrophysics Data System (ADS)

    Moberly, D.; Maki, L.; Hill, K. M.

    2014-12-01

    As debris flows course down a steep hillside they entrain bed materials such as loose sediments. The entrainment of materials not only increases the size of the debris flows but the mobility as well. The mechanics underlying the particle entrainment and the associated increased mobility are not well-understood. Existing models for the entrainment process include those that explicitly consider stress ratios, the angle of inclination, and the particle fluxes relative to those achieved under steady conditions. Others include an explicit consideration of the physics of the granular state: the visco-elastic nature of particle flows and, alternatively, the role of macroscopic force chains. Understanding how well these different approaches account for entrainment and deposition rates is important for accurate debris flow modeling, both in terms of the rate of growth and also in terms of the increased mobility associated with the entrainment. We investigate how total and instantaneous entrainment and deposition vary with macroscopic stresses and particle-scale interactions for different particle sizes and different fluid contents using laboratory experiments in an instrumented experimental laboratory debris flow flume. The flume has separate, independent water supplies for the bed and "supply" (parent debris flow), and the bed is instrumented with pore pressure sensors and a basal stress transducer. We monitor flow velocities, local structure, and instantaneous entrainment and deposition rates using a high speed camera. We have found that systems with a mixture of particle sizes are less erosive and more depositional than systems of one particle size under otherwise the same conditions. For both mixtures and single-sized particle systems, we have observed a relatively linear relationship between total erosion and the slope angle for dry flows. Increasing fluid content typically increases entrainment. Measurements of instantaneous entrainment indicate similar dependencies

  15. Speech entrainment compensates for Broca's area damage.

    PubMed

    Fridriksson, Julius; Basilakos, Alexandra; Hickok, Gregory; Bonilha, Leonardo; Rorden, Chris

    2015-08-01

    Speech entrainment (SE), the online mimicking of an audiovisual speech model, has been shown to increase speech fluency in patients with Broca's aphasia. However, not all individuals with aphasia benefit from SE. The purpose of this study was to identify patterns of cortical damage that predict a positive response SE's fluency-inducing effects. Forty-four chronic patients with left hemisphere stroke (15 female) were included in this study. Participants completed two tasks: 1) spontaneous speech production, and 2) audiovisual SE. Number of different words per minute was calculated as a speech output measure for each task, with the difference between SE and spontaneous speech conditions yielding a measure of fluency improvement. Voxel-wise lesion-symptom mapping (VLSM) was used to relate the number of different words per minute for spontaneous speech, SE, and SE-related improvement to patterns of brain damage in order to predict lesion locations associated with the fluency-inducing response to SE. Individuals with Broca's aphasia demonstrated a significant increase in different words per minute during SE versus spontaneous speech. A similar pattern of improvement was not seen in patients with other types of aphasia. VLSM analysis revealed damage to the inferior frontal gyrus predicted this response. Results suggest that SE exerts its fluency-inducing effects by providing a surrogate target for speech production via internal monitoring processes. Clinically, these results add further support for the use of SE to improve speech production and may help select patients for SE treatment. PMID:25989443

  16. Granular motions near the threshold of entrainment

    NASA Astrophysics Data System (ADS)

    Valyrakis, Manousos; Alexakis, athanasios-Theodosios

    2016-04-01

    Our society is continuously impacted by significant weather events many times resulting in catastrophes that interrupt our normal way of life. In the context of climate change and increasing urbanisation these "extreme" hydrologic events are intensified both in magnitude and frequency, inducing costs of the order of billions of pounds. The vast majority of such costs and impacts (even more to developed societies) are due to water related catastrophes such as the geomorphic action of flowing water (including scouring of critical infrastructure, bed and bank destabilisation) and flooding. New tools and radically novel concepts are in need, to enable our society becoming more resilient. This presentation, emphasises the utility of inertial sensors in gaining new insights on the interaction of flow hydrodynamics with the granular surface at the particle scale and for near threshold flow conditions. In particular, new designs of the "smart-sphere" device are discussed with focus on the purpose specific sets of flume experiments, designed to identify the exact response of the particle resting at the bed surface for various below, near and above threshold flow conditions. New sets of measurements are presented for particle entrainment from a Lagrangian viewpoint. Further to finding direct application in addressing real world challenges in the water sector, it is shown that such novel sensor systems can also help the research community (both experimentalists and computational modellers) gain a better insight on the underlying processes governing granular dynamics.

  17. Superior power density solid oxide fuel cells by enlarging the three-phase boundary region of a NiO-Ce0.8Gd0.2O1.9 composite anode through optimized surface structure.

    PubMed

    Yoon, Daeil; Su, Qing; Wang, Haiyan; Manthiram, Arumugam

    2013-09-28

    In an effort to boost the power densities of solid oxide fuel cells (SOFCs) operating at intermediate temperatures (600-750 °C), novel powder synthesis methods have been studied with the goal of increasing the three-phase boundary region of the anode. Porous anodes composed of Ni and Ce0.8Gd0.2O1.9 (GDC) cermet are commonly studied in SOFCs, but the cell performance is limited by their dependency on the three-phase boundaries at which the electrochemical oxidation reaction takes place. This paper presents a remarkable improvement in the electrochemical performance through a significant enlargement of the three-phase boundary region by an optimization of the surface structure. The strategy starts with the premise that the oxide powder particles in aqueous solution carry a positive or negative electrical charge depending upon the pH of the solution, and the charge can be exploited to attach chelated metal ions to their surface, extending the three-phase boundary region. This modified NiO-GDC composite powder resulted in not only an extension of both electronic and O(2-) ionic conduction pathways, but also a suppression of grain growth in the anode during the process of cell fabrication. As the final outcome, the modified Ni-GDC anode-supported cells show far superior power densities (1.85 W cm(-2) at 750 °C and 0.83 W cm(-2) at 600 °C) in H2 compared to the conventional Ni-GDC anode-supported cells (0.61 W cm(-2) at 750 °C and 0.26 W cm(-2) at 600 °C). PMID:23907182

  18. Strong effects of network architecture in the entrainment of coupled oscillator systems

    NASA Astrophysics Data System (ADS)

    Kori, Hiroshi; Mikhailov, Alexander S.

    2006-12-01

    Random networks of coupled phase oscillators, representing an approximation for systems of coupled limit-cycle oscillators, are considered. Entrainment of such networks by periodic external forcing applied to a subset of their elements is numerically and analytically investigated. For a large class of interaction functions, we find that the entrainment window with a tongue shape becomes exponentially narrow for networks with higher hierarchical organization. However, the entrainment is significantly facilitated if the networks are directionally biased—i.e., closer to the feedforward networks. Furthermore, we show that the networks with high entrainment ability can be constructed by evolutionary optimization processes. The neural network structure of the master clock of the circadian rhythm in mammals is discussed from the viewpoint of our results.

  19. Individual Differences in Rhythmic Cortical Entrainment Correlate with Predictive Behavior in Sensorimotor Synchronization.

    PubMed

    Nozaradan, Sylvie; Peretz, Isabelle; Keller, Peter E

    2016-01-01

    The current study aims at characterizing the mechanisms that allow humans to entrain the mind and body to incoming rhythmic sensory inputs in real time. We addressed this unresolved issue by examining the relationship between covert neural processes and overt behavior in the context of musical rhythm. We measured temporal prediction abilities, sensorimotor synchronization accuracy and neural entrainment to auditory rhythms as captured using an EEG frequency-tagging approach. Importantly, movement synchronization accuracy with a rhythmic beat could be explained by the amplitude of neural activity selectively locked with the beat period when listening to the rhythmic inputs. Furthermore, stronger endogenous neural entrainment at the beat frequency was associated with superior temporal prediction abilities. Together, these results reveal a direct link between cortical and behavioral measures of rhythmic entrainment, thus providing evidence that frequency-tagged brain activity has functional relevance for beat perception and synchronization. PMID:26847160

  20. Individual Differences in Rhythmic Cortical Entrainment Correlate with Predictive Behavior in Sensorimotor Synchronization

    PubMed Central

    Nozaradan, Sylvie; Peretz, Isabelle; Keller, Peter E.

    2016-01-01

    The current study aims at characterizing the mechanisms that allow humans to entrain the mind and body to incoming rhythmic sensory inputs in real time. We addressed this unresolved issue by examining the relationship between covert neural processes and overt behavior in the context of musical rhythm. We measured temporal prediction abilities, sensorimotor synchronization accuracy and neural entrainment to auditory rhythms as captured using an EEG frequency-tagging approach. Importantly, movement synchronization accuracy with a rhythmic beat could be explained by the amplitude of neural activity selectively locked with the beat period when listening to the rhythmic inputs. Furthermore, stronger endogenous neural entrainment at the beat frequency was associated with superior temporal prediction abilities. Together, these results reveal a direct link between cortical and behavioral measures of rhythmic entrainment, thus providing evidence that frequency-tagged brain activity has functional relevance for beat perception and synchronization. PMID:26847160

  1. Process Developed for Fabricating Engineered Pore Structures for High- Fuel-Utilization Solid Oxide Fuel Cells

    NASA Technical Reports Server (NTRS)

    Sofie, Stephen W.; Cable, Thomas L.; Salamone, Sam M.

    2005-01-01

    Solid oxide fuel cells (SOFCs) have tremendous commercial potential because of their high efficiency, high energy density, and flexible fuel capability (ability to use fossil fuels). The drive for high-power-utilizing, ultrathin electrolytes (less than 10 microns), has placed an increased demand on the anode to provide structural support, yet allow sufficient fuel entry for sustained power generation. Concentration polarization, a condition where the fuel demand exceeds the supply, is evident in all commercial-based anode-supported cells, and it presents a significant roadblock to SOFC commercialization.

  2. An Update on NiCE Support for BISON

    SciTech Connect

    McCaskey, Alex; Billings, Jay Jay; Deyton, Jordan H.; Wojtowicz, Anna

    2015-09-01

    The Nuclear Energy Advanced Modeling and Simulation program (NEAMS) from the Department of Energy s Office of Nuclear Energy has funded the development of a modeling and simulation workflow environment to support the various codes in its nuclear energy scientific computing toolkit. This NEAMS Integrated Computational Environment (NiCE) provides extensible tools and services that enable efficient code execution, input generation, pre-processing visualizations, and post-simulation data analysis and visualization for a large portion of the NEAMS Toolkit. A strong focus for the NiCE development team throughout FY 2015 has been support for the Multiphysics Object Oriented Simulation Environment (MOOSE) and the NEAMS nuclear fuel performance modeling application built on that environment, BISON. There is a strong desire in the program to enable and facilitate the use of BISON throughout nuclear energy research and industry. A primary result of this desire is the need for strong support for BISON in NiCE. This report will detail improvements to NiCE support for BISON. We will present a new and improved interface for interacting with BISON simulations in a variety of ways: (1) improved input model generation, (2) embedded mesh and solution data visualizations, and (3) local and remote BISON simulation launch. We will also show how NiCE has been extended to provide support for BISON code development.

  3. Nonphotic entrainment of the human circadian pacemaker

    NASA Technical Reports Server (NTRS)

    Klerman, E. B.; Rimmer, D. W.; Dijk, D. J.; Kronauer, R. E.; Rizzo, J. F. 3rd; Czeisler, C. A.

    1998-01-01

    In organisms as diverse as single-celled algae and humans, light is the primary stimulus mediating entrainment of the circadian biological clock. Reports that some totally blind individuals appear entrained to the 24-h day have suggested that nonphotic stimuli may also be effective circadian synchronizers in humans, although the nonphotic stimuli are probably comparatively weak synchronizers, because the circadian rhythms of many totally blind individuals "free run" even when they maintain a 24-h activity-rest schedule. To investigate entrainment by nonphotic synchronizers, we studied the endogenous circadian melatonin and core body temperature rhythms of 15 totally blind subjects who lacked conscious light perception and exhibited no suppression of plasma melatonin in response to ocular bright-light exposure. Nine of these fifteen blind individuals were able to maintain synchronization to the 24-h day, albeit often at an atypical phase angle of entrainment. Nonphotic stimuli also synchronized the endogenous circadian rhythms of a totally blind individual to a non-24-h schedule while living in constant near darkness. We conclude that nonphotic stimuli can entrain the human circadian pacemaker in some individuals lacking ocular circadian photoreception.

  4. On dust entrainment in photoevaporative winds

    NASA Astrophysics Data System (ADS)

    Hutchison, Mark A.; Price, Daniel J.; Laibe, Guillaume; Maddison, Sarah T.

    2016-09-01

    We investigate dust entrainment by photoevaporative winds in protoplanetary discs using dusty smoothed particle hydrodynamics. We use unequal-mass particles to resolve more than five orders of magnitude in disc/outflow density and a one-fluid formulation to efficiently simulate an equivalent magnitude range in drag stopping time. We find that only micron-sized dust grains and smaller can be entrained in extreme-UV radiation-driven winds. The maximum grain size is set by dust settling in the disc rather than aerodynamic drag in the wind. More generally, there is a linear relationship between the base flow density and the maximum entrainable grain size in the wind. A pileup of micron-sized dust grains can occur in the upper atmosphere at critical radii in the disc as grains decouple from the low-density wind. Entrainment is a strong function of location in the disc, resulting in a size sorting of grains in the outflow - the largest grain being carried out between 10 and 20 au. The peak dust density for each grain size occurs at the inner edge of its own entrainment region.

  5. Entrainment and the cranial rhythmic impulse.

    PubMed

    McPartland, J M; Mein, E A

    1997-01-01

    Entrainment is the integration or harmonization of oscillators. All organisms pulsate with myriad electrical and mechanical rhythms. Many of these rhythms emanate from synchronized pulsating cells (eg, pacemaker cells, cortical neurons). The cranial rhythmic impulse is an oscillation recognized by many bodywork practitioners, but the functional origin of this impulse remains uncertain. We propose that the cranial rhythmic impulse is the palpable perception of entrainment, a harmonic frequency that incorporates the rhythms of multiple biological oscillators. It is derived primarily from signals between the sympathetic and parasympathetic nervous systems. Entrainment also arises between organisms. The harmonizing of coupled oscillators into a single, dominant frequency is called frequency-selective entrainment. We propose that this phenomenon is the modus operandi of practitioners who use the cranial rhythmic impulse in craniosacral treatment. Dominant entrainment is enhanced by "centering," a technique practiced by many healers, for example, practitioners of Chinese, Tibetan, and Ayurvedic medicine. We explore the connections between centering, the cranial rhythmic impulse, and craniosacral treatment. PMID:8997803

  6. Fate of virginiamycin through the fuel ethanol production process.

    PubMed

    Bischoff, Kenneth M; Zhang, Yanhong; Rich, Joseph O

    2016-05-01

    Antibiotics are frequently used to prevent and treat bacterial contamination of commercial fuel ethanol fermentations, but there is concern that antibiotic residues may persist in the distillers grains coproducts. A study to evaluate the fate of virginiamycin during the ethanol production process was conducted in the pilot plant facilities at the National Corn to Ethanol Research Center, Edwardsville, IL. Three 15,000-liter fermentor runs were performed: one with no antibiotic (F1), one dosed with 2 parts per million (ppm) of a commercial virginiamycin product (F2), and one dosed at 20 ppm of virginiamycin product (F3). Fermentor samples, distillers dried grains with solubles (DDGS), and process intermediates (whole stillage, thin stillage, syrup, and wet cake) were collected from each run and analyzed for virginiamycin M and virginiamycin S using a liquid chromatography-mass spectrometry method. Virginiamycin M was detected in all process intermediates of the F3 run. On a dry-weight basis, virginiamycin M concentrations decreased approximately 97 %, from 41 μg/g in the fermentor to 1.4 μg/g in the DDGS. Using a disc plate bioassay, antibiotic activity was detected in DDGS from both the F2 and F3 runs, with values of 0.69 μg virginiamycin equivalent/g sample and 8.9 μg/g, respectively. No antibiotic activity (<0.6 μg/g) was detected in any of the F1 samples or in the fermentor and process intermediate samples from the F2 run. These results demonstrate that low concentrations of biologically active antibiotic may persist in distillers grains coproducts produced from fermentations treated with virginiamycin. PMID:27038946

  7. Process for making a martensitic steel alloy fuel cladding product

    DOEpatents

    Johnson, Gerald D.; Lobsinger, Ralph J.; Hamilton, Margaret L.; Gelles, David S.

    1990-01-01

    This is a very narrowly defined martensitic steel alloy fuel cladding material for liquid metal cooled reactors, and a process for making such a martensitic steel alloy material. The alloy contains about 10.6 wt. % chromium, about 1.5 wt. % molybdenum, about 0.85 wt. % manganese, about 0.2 wt. % niobium, about 0.37 wt. % silicon, about 0.2 wt. % carbon, about 0.2 wt. % vanadium, 0.05 maximum wt. % nickel, about 0.015 wt. % nitrogen, about 0.015 wt. % sulfur, about 0.05 wt. % copper, about 0.007 wt. % boron, about 0.007 wt. % phosphorous, and with the remainder being essentially iron. The process utilizes preparing such an alloy and homogenizing said alloy at about 1000.degree. C. for 16 hours; annealing said homogenized alloy at 1150.degree. C. for 15 minutes; and tempering said annealed alloy at 700.degree. C. for 2 hours. The material exhibits good high temperature strength (especially long stress rupture life) at elevated temperature (500.degree.-760.degree. C.).

  8. Disposition of salt-waste from pyrochemical nuclear fuel processing

    SciTech Connect

    Vance, E.R.

    2007-07-01

    Waste salts from pyrochemical processing of nuclear fuel can be immobilised in sodalite if consolidated by hot isostatic pressing (HIP) at {approx}750 deg. C/100 MPa in thick stainless steel 316 cans. Other canning materials for this purpose also look possible. Spodiosite-based waste forms do not look promising in terms of leach resistance and their incorporation of alkali ions and compatibility with other phases which could potentially accommodate fission products, such as NaZr{sub 2}(PO{sub 4}){sub 3} or alumino-phosphate glass. Chloro- or fluor-apatite-based waste forms however have been reported to successfully accommodate fission products and alkalis which would be derived from either chloride- or fluoride-based waste pyro-processing salts. The presence of 10 or 20 wt% of additional Whitlockite, Ca{sub 3}(PO{sub 4}){sub 2}, should allow chemical flexibility to maintain the same qualitative phase assemblage when there are variations in the waste feed and in the waste/precursor ratios. Experimental verification of incorporation of the full complement of waste salts and fission products is not yet complete however. Apatite-rich samples could likely be HIPed in Inconel 600 cans. Other candidate HIP canning materials such as Alloy 22 or Inconel 625 are under study by encapsulating them in the candidate waste form and studying their interaction or otherwise with the waste form. (author)

  9. Potential synergy: the thorium fuel cycle and rare earths processing

    SciTech Connect

    Ault, T.; Wymer, R.; Croff, A.; Krahn, S.

    2013-07-01

    The use of thorium in nuclear power programs has been evaluated on a recurring basis. A concern often raised is the lack of 'thorium infrastructure'; however, for at least a part of a potential thorium fuel cycle, this may less of a problem than previously thought. Thorium is frequently encountered in association with rare earth elements and, since the U.S. last systematically evaluated the large-scale use of thorium (the 1970's,) the use of rare earth elements has increased ten-fold to approximately 200,000 metric tons per year. Integration of thorium extraction with rare earth processing has been previously described and top-level estimates have been done on thorium resource availability; however, since ores and mining operations differ markedly, what is needed is process flowsheet analysis to determine whether a specific mining operation can feasibly produce thorium as a by-product. Also, the collocation of thorium with rare earths means that, even if a thorium product stream is not developed, its presence in mining waste streams needs to be addressed and there are previous instances where this has caused issues. This study analyzes several operational mines, estimates the mines' ability to produce a thorium by-product stream, and discusses some waste management implications of recovering thorium. (authors)

  10. Entrainment of respiratory frequency to exercise rhythm during hypoxia.

    PubMed

    Paterson, D J; Wood, G A; Marshall, R N; Morton, A R; Harrison, A B

    1987-05-01

    Breathing frequency (f) is often reported as having an integer-multiple relationship to limb movement (entrainment) during rhythmic exercise. To investigate the strength of this coupling while running under hypoxic conditions, two male Caucasians and four male Nepalese porters were tested in the Annapurna region of the Himalayas at altitudes of 915, 2,135, 3,200, 4,420, and 5,030 m. In an additional study in a laboratory at sea level, three male and four female subjects inspired various O2-N2 mixtures [fraction of inspired O2 (FIO2) = 20.93, 17.39, 14.40, 11.81%] that were administered in a single-blind randomized fashion during a treadmill run (40% FIO2 maximum O2 consumption). Breathing and gait signals were stored on FM tape and later processed on a PDP 11/73 computer. The subharmonic relationships between these signals were determined from Fourier analysis (power spectrum), and the coincidence of coupling occurrence was statistically modeled. Entrainment decreased linearly during increasing hypoxia (P less than 0.01). Moreover, a significant linear increase in f occurred during hypoxia (P less than 0.05), whereas stride frequency and metabolic rate remained constant, suggesting that hypoxic-induced increases in f decreased the degree of entrainment. PMID:3597249

  11. Rhythm as a Coordinating Device: Entrainment With Disordered Speech

    PubMed Central

    Borrie, Stephanie A.; Liss, Julie M.

    2014-01-01

    Purpose The rhythmic entrainment (coordination) of behavior during human interaction is a powerful phenomenon, considered essential for successful communication, supporting social and emotional connection, and facilitating sense-making and information exchange. Disruption in entrainment likely occurs in conversations involving those with speech and language impairment, but its contribution to communication disorders has not been defined. As a first step to exploring this phenomenon in clinical populations, the present investigation examined the influence of disordered speech on the speech production properties of healthy interactants. Method Twenty-nine neurologically healthy interactants participated in a quasi-conversational paradigm, in which they read sentences (response) in response to hearing prerecorded sentences (exposure) from speakers with dysarthria (n = 4) and healthy controls (n = 4). Recordings of read sentences prior to the task were also collected (habitual). Results Findings revealed that interactants modified their speaking rate and pitch variation to align more closely with the disordered speech. Production shifts in these rhythmic properties, however, remained significantly different from corresponding properties in dysarthric speech. Conclusion Entrainment offers a new avenue for exploring speech and language impairment, addressing a communication process not currently explained by existing frameworks. This article offers direction for advancing this line of inquiry. PMID:24686410

  12. Velocity response curves demonstrate the complexity of modeling entrainable clocks.

    PubMed

    Taylor, Stephanie R; Cheever, Allyson; Harmon, Sarah M

    2014-12-21

    Circadian clocks are biological oscillators that regulate daily behaviors in organisms across the kingdoms of life. Their rhythms are generated by complex systems, generally involving interlocked regulatory feedback loops. These rhythms are entrained by the daily light/dark cycle, ensuring that the internal clock time is coordinated with the environment. Mathematical models play an important role in understanding how the components work together to function as a clock which can be entrained by light. For a clock to entrain, it must be possible for it to be sped up or slowed down at appropriate times. To understand how biophysical processes affect the speed of the clock, one can compute velocity response curves (VRCs). Here, in a case study involving the fruit fly clock, we demonstrate that VRC analysis provides insight into a clock׳s response to light. We also show that biochemical mechanisms and parameters together determine a model׳s ability to respond realistically to light. The implication is that, if one is developing a model and its current form has an unrealistic response to light, then one must reexamine one׳s model structure, because searching for better parameter values is unlikely to lead to a realistic response to light. PMID:25193284

  13. Impregnation of La0.4Ce0.6O1.8-La0.4Sr0.6TiO3 as solid oxide fuel cell anode in H2S-containing fuels

    NASA Astrophysics Data System (ADS)

    Afshar, Milad R.; Yan, Ning; Zahiri, Beniamin; Mitlin, David; Chuang, Karl T.; Luo, Jing-Li

    2015-01-01

    Active anodes were fabricated via wet chemical impregnation of optimized amount of La0.4Sr0.6TiO3 (L4ST) into La0.4Ce0.6O1.8 (LDC) pre-infiltrated porous yttria-stabilized zirconia (YSZ) matrix. Impregnations of 10 wt% LDC with 16 wt% L4ST significantly improved the performance of the fuel cell from 48 mW cm-2 for pure L4ST to 161 mW cm-2 for LDC-L4ST at 900 °C in H2. The contribution of the pre-loaded LDC to this improvement was investigated using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM). The measurement results indicated that pre-infiltrated LDC increased the activity of the anode more effectively by decreasing the total polarization resistance of the cell from 3.3 Ω cm2 to 1.0 Ω cm2 in humidified H2 at 900 °C. More importantly, the LDC nano-deposits (<20 nm) behaved as an effective "adhesive" that substantially enhanced the wettability of L4ST on YSZ matrix, resulting in finer and more uniform structure of L4ST infiltrates. The LDC-L4ST cells also demonstrated significantly improved performances in 0.5% H2S-H2 and 0.5% H2S-CH4 with higher stability than cells with pure L4ST anode.

  14. Numerical Modeling of Deep Mantle Flow: Thermochemical Convection and Entrainment

    NASA Astrophysics Data System (ADS)

    Mulyukova, Elvira; Steinberger, Bernhard; Dabrowski, Marcin; Sobolev, Stephan

    2013-04-01

    ) upwelling of the ambient material in the vicinity of the dense material (mechanism of selective withdrawal (Lister, 1989)), and (iii) cold downwellings sliding along the bottom boundary, and forcing the dense material upwards. The objective of this study is to compare the efficiency of entrainment by each of these mechanisms, and its dependence on the density and viscosity anomaly of the dense material with respect to the ambient mantle. To perform this study, we have developed a two-dimensional FEM code to model thermal convection in a hollow cylinder domain with presence of chemical heterogeneities, and using a realistic viscosity profile. We present the results of the simulations that demonstrate the entrainment mechanisms described above. In addition, we perfom numerical experiments in a Cartesian box domain, where the bottom right boundary of the box is deformed to resemble the geometry of an LLSVP edge. In some of the experiments, the bottom left part of the boundary is moving towards the right boundary, simulating a slab sliding along the core-mantle boundary towards an LLSVP. These experiments allow a detailed study of the process of entrainment, and its role in the thermochemical evolution of the Earth.

  15. Development of OTM Syngas Process and Testing of Syngas Derived Ultra-clean Fuels in Diesel Engines and Fuel Cells

    SciTech Connect

    E.T. Robinson; James P. Meagher; Prasad Apte; Xingun Gui; Tytus R. Bulicz; Siv Aasland; Charles Besecker; Jack Chen Bart A. van Hassel; Olga Polevaya; Rafey Khan; Piyush Pilaniwalla

    2002-12-31

    This topical report summarizes work accomplished for the Program from November 1, 2001 to December 31, 2002 in the following task areas: Task 1: Materials Development; Task 2: Composite Development; Task 4: Reactor Design and Process Optimization; Task 8: Fuels and Engine Testing; 8.1 International Diesel Engine Program; 8.2 Nuvera Fuel Cell Program; and Task 10: Program Management. Major progress has been made towards developing high temperature, high performance, robust, oxygen transport elements. In addition, a novel reactor design has been proposed that co-produces hydrogen, lowers cost and improves system operability. Fuel and engine testing is progressing well, but was delayed somewhat due to the hiatus in program funding in 2002. The Nuvera fuel cell portion of the program was completed on schedule and delivered promising results regarding low emission fuels for transportation fuel cells. The evaluation of ultra-clean diesel fuels continues in single cylinder (SCTE) and multiple cylinder (MCTE) test rigs at International Truck and Engine. FT diesel and a BP oxygenate showed significant emissions reductions in comparison to baseline petroleum diesel fuels. Overall through the end of 2002 the program remains under budget, but behind schedule in some areas.

  16. Transcriptome Changes in Douglas-fir (Pseudotsuga menziesii) Induced by Exposure to Diesel Emissions Generated with CeO2 Nanoparticle Fuel Additive

    EPA Science Inventory

    When cerium oxide nanoparticles are added to diesel fuel, fuel burning efficiency increases, producing emissions (DECe) with characteristics that differ from conventional diesel exhaust (DE). It has previously been shown that DECe induces more adverse pulmonary effects in rats on...

  17. Improved activity and stability of Ni-Ce0.8Sm0.2O1.9 anode for solid oxide fuel cells fed with methanol through addition of molybdenum

    NASA Astrophysics Data System (ADS)

    Li, Ping; Yu, Baolong; Li, Jiang; Yao, Xueli; Zhao, Yicheng; Li, Yongdan

    2016-07-01

    Ni-Mo-Ce0.8Sm0.2O1.9 (SDC) composites are prepared and investigated as anodes of solid oxide fuel cells with methanol as fuel. The addition of Mo improves the catalytic activity for methanol pyrolysis and the resistance to carbon deposition of Ni-SDC anode. The anode with a mole ratio of Mo to Ni of 0.03:1 exhibits the lowest polarization resistance. The cell with that anode and SDC-carbonate composite electrolyte shows a maximum power density of 680 mW cm-2 at 700 °C. The stability of the cell is enhanced with the increase of the content of Mo in the anode, which is mainly attributed to the decreased amount of carbon deposits with a high graphitization degree.

  18. Food entrainment: major and recent findings

    PubMed Central

    Carneiro, Breno T. S.; Araujo, John F.

    2012-01-01

    Mammals exhibit daily anticipatory activity to cycles of food availability. Studies on such food anticipatory activity (FAA) have been conducted mainly in nocturnal rodents. They have identified FAA as the behavioral output of a food entrained oscillator (FEO), separate of the known light entrained oscillator (LEO) located in the suprachiasmatic nucleus (SCN) of hypothalamus. Here we briefly review the main characteristics of FAA. Also, we present results on four topics of food anticipation: (1) possible input signals to FEO, (2) FEO substrate, (3) the importance of canonical clock genes for FAA, and (4) potential practical applications of scheduled feeding. This mini review is intended to introduce the subject of food entrainment to those unfamiliar with it but also present them with relevant new findings on the issue. PMID:23205007

  19. Flowmeter for gas-entrained solids flow

    DOEpatents

    Porges, Karl G.

    1990-01-01

    An apparatus and method for the measurement of solids feedrate in a gas-entrained solids flow conveyance system. The apparatus and method of the present invention include a vertical duct connecting a source of solids to the gas-entrained flow conveyance system, a control valve positioned in the vertical duct, and a capacitive densitometer positioned along the duct at a location a known distance below the control valved so that the solid feedrate, Q, of the gas entrained flow can be determined by Q=S.rho..phi.V.sub.S where S is the cross sectional area of the duct, .rho. is the density of the solid, .phi. is the solid volume fraction determined by the capacitive densitometer, and v.sub.S is the local solid velocity which can be inferred from the konown distance of the capacitive densitometer below the control valve.

  20. Resonant entrainment of a confined pulsed jet

    NASA Technical Reports Server (NTRS)

    Parikh, P. G.; Moffat, R. J.

    1982-01-01

    This paper reports the discovery of a new resonant entrainment phenomenon associated with a confined, pulsed jet flow. It was found that a confined jet, when pulsed at an organ-pipe resonant frequency of the confinement tube, experiences greatly enhanced entrainment and mixing near the exit end of the confinement tube compared to a steady confined jet. The mixing and entrainment rates for the resonantly pulsed confined jet approach, and in some cases slightly exceed, those for an unconfined pulsed jet. Both visual and quantitative evidence of this phenomenon is presented. The new effect should be of considerable interest in ejector and combustor design, both of which benefit from any enhancement in mixing between a primary and a secondary flow

  1. Thermochemical Processing of Radioactive Waste Using Powder Metal Fuels

    SciTech Connect

    Ojovan, M. I.; Sobolev, I. A.; Dmitriev, S. A.; Panteleev, V. I.; Karlina, O. K.; Klimov. V. L.

    2003-02-25

    Problematic radioactive wastes were generated during various activities of both industrial facilities and research institutions usually in relative small amounts. These can be spent ion exchange resins, inorganic absorbents, wastes from research nuclear reactors, irradiated graphite, mixed, organic or chlorine-containing radioactive waste, contaminated soils, un-burnable heavily surface-contaminated materials, etc. Conventional treatment methods encounter serious problems concerning processing efficiency of such waste, e.g. complete destruction of organic molecules and avoiding of possible emissions of radionuclides, heavy metals and chemically hazardous species. Some contaminations cannot be removed from surface using common decontamination methods. Conditioning of ash residues obtained after treatment of solid radioactive waste including ashes received from treating problematic wastes also is a complicated task. Moreover due to relative small volume of specific type radioactive waste the development of target treatment procedures and facilities to conduct technological processes and their deployment could be economically unexpedient and ecologically no justified. Thermochemical processing technologies are used for treating and conditioning problematic radioactive wastes. The thermochemical processing uses powdered metal fuels (PMF) that are specifically formulated for the waste composition and react chemically with the waste components. The composition of the PMF is designed in such a way as to minimize the release of hazardous components and radionuclides in the off gas and to confine the contaminants in the ash residue. The thermochemical procedures allow decomposition of organic matter and capturing hazardous radionuclides and chemical species simultaneously. A significant advantage of thermochemical processing is its autonomy. Thermochemical treatment technologies use the energy of exothermic reactions in the mixture of radioactive or hazardous waste with PMF

  2. The Photoluminescence Properties of CaYAI₃O₇:Ce³⁺, Tb³⁺, Sm³⁺ Prepared by the Sol-Gel Process.

    PubMed

    Xiumei, Han; Xin, Yan; Jianquan, Qi; Xiwei, Qi; Xiaoqiang, Wang; Mingya, Li; Xudong, Sun; Chen, Wei

    2016-01-01

    This paper reports the synthesis and luminescence properties of rare earth doped CaYAI₃O₇ prepared via a sol-gel process. The phosphors have intense luminescence. In Ce³⁺/Tb³⁺ co-doped materials, there is energy transfer from Ce³⁺ to Tb³⁺ that enhances the luminescence of Tb³⁺. These materials may find applications in solid state lighting and radiation detection. PMID:27398514

  3. Microstructural and metal-support interactions of the Pt-CeO2/C catalysts for direct methanol fuel cell application.

    PubMed

    Ou, Ding Rong; Mori, Toshiyuki; Togasaki, Hirotaka; Takahashi, Motoi; Ye, Fei; Drennan, John

    2011-04-01

    To understand the ceria promotion effect of Pt-CeO(2)/C catalysts on methanol oxidation, microstructural and metal-oxide interactions of Pt-CeO(2)/C catalysts with an atomic ratio of Pt/Ce between 0.14 and 1.4 were systematically examined using high-resolution transmission electron microscopy and electron energy loss spectroscopy (EELS). With an increasing Pt content in the catalysts, Pt particles gradually invaded into the ceria supports and decoration on Pt particles was observed. Simultaneously, the morphology of the supports was dramatically modified with nanocrystalline and amorphous ceria formed between and/or around the Pt particles. It reveals that the Pt-ceria interaction could take place in the catalysts and the influence of the interaction was enhanced with an increasing Pt/Ce ratio. The EELS study demonstrated that the strong Pt-ceria interaction was related to the redox reaction between Pt and ceria. Experimental results also suggested that the strong interaction between Pt and ceria could contribute to the promotion effect of ceria on the oxidation of methanol. PMID:21395272

  4. Ozone conservation and entrainment in cumulus congestus

    NASA Technical Reports Server (NTRS)

    Pearson, R., Jr.; Weaver, C. J.

    1989-01-01

    This study demonstrates that ozone mixing ratio is conserved during moist convection and can be used as a tracer for cloud entrainment studies. The approach is to apply mixing line analysis to pairs of liquid water potential temperature, total water mixing ratio, O3 and pseudo-equivalent potential temperature derived from aircraft penetrations of growing cumulus congestus. Conclusions about entrainment from the mixing diagrams employing O3 agree with those using thermodynamic quantities. Any disagreement uncovered deficiencies in the water substance measurement technique.

  5. Fuel quality-processing study. Volume 1: Overview and results

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.

    1982-01-01

    The methods whereby the intermediate results were obtained are outlined, and the evaluation of the feasible paths from liquid fossil fuel sources to generated electricity is presented. The segments from which these paths were built are the results from the fuel upgrading schemes, on-site treatments, and exhaust gas treatments detailed in the subsequent volumes. The salient cost and quality parameters are included.

  6. Process for making film-bonded fuel cell interfaces

    DOEpatents

    Kaufman, Arthur; Terry, Peter L.

    1990-07-03

    An improved interface configuration for use between adjacent elements of a fuel cell stack. The interface is impervious to gas and liquid and provides resistance to corrosion by the electrolyte of the fuel cell. A multi-layer arrangement for the interface provides bridging electrical contact with a hot-pressed resin filling the void space.

  7. Entrainment of riparian gravel and cobbles in an alluvial reach of a regulated canyon river

    USGS Publications Warehouse

    Elliotp, J.G.; Hammack, L.A.

    2000-01-01

    Many canyon rivers have channels and riparian zones composed of alluvial materials and these reaches, dominated by fluvial processes, are sensitive to alterations in streamflow regime. Prior to reservoir construction in the mid-1960s, banks and bars in alluvial reaches of the Gunnison River in the Black Canyon National Monument, Colorado, USA, periodically were reworked and cleared of riparian vegetation by mainstem floods. Recent interest in maintaining near-natural conditions in the Black Canyon using reservoir releases has created a need to estimate sediment-entraining discharges for a variety of geomorphic surfaces composed of sediment ranging in size from gravel to small boulders. Sediment entrainment potential was studied at eight cross-sections in an alluvial reach of the Gunnison River in the Black Canyon in 1994 and 1995. A one-dimensional water-surface profile model was used to estimate water-surface elevations, flow depths, and hydraulic conditions on selected alluvial surfaces for discharges ranging from 57 to 570 m3/s. Onsite observations before and after a flood of 270 m3/s confirmed sediment entrainment on several surfaces inundated by the flood. Selective entrainment of all but the largest particle sizes on the surface occurred at some locations. Physical evidence of sediment entrainment, or absence of sediment entrainment, on inundated surfaces generally was consistent with critical shear stresses estimated with a dimensionless critical shear stress of 0.030. Sediment-entrainment potential over a range of discharges was summarized by the ratio of the local boundary shear stress to the critical shear stress for d50, given hydraulic geometry and sediment-size characteristics. Differing entrainment potential for similar geomorphic surfaces indicates that estimation of minimum streamflow requirements based on sediment mobility is site-specific and that there is no unique streamflow that will initiate movement of d50 at every geomorphically similar

  8. Selective perceptual phase entrainment to speech rhythm in the absence of spectral energy fluctuations.

    PubMed

    Zoefel, Benedikt; VanRullen, Rufin

    2015-02-01

    Perceptual phase entrainment improves speech intelligibility by phase-locking the brain's high-excitability and low-excitability phases to relevant or irrelevant events in the speech input. However, it remains unclear whether phase entrainment to speech can be explained by a passive "following" of rhythmic changes in sound amplitude and spectral content or whether entrainment entails an active tracking of higher-level cues: in everyday speech, rhythmic fluctuations in low-level and high-level features always covary. Here, we resolve this issue by constructing novel speech/noise stimuli with intelligible speech but without systematic changes in sound amplitude and spectral content. The probability of detecting a tone pip, presented to human listeners at random moments during our speech/noise stimuli, was significantly modulated by the rhythmic changes in high-level information. Thus, perception can entrain to the speech rhythm even without concurrent fluctuations in sound amplitude or spectral content. Strikingly, the actual entrainment phase depended on the tone-pip frequency, with tone pips within and beyond the principal frequency range of the speech sound modulated in opposite fashion. This result suggests that only those neural populations processing the actually presented frequencies are set to their high-excitability phase, whereas other populations are entrained to the opposite, low-excitability phase. Furthermore, we show that the perceptual entrainment is strongly reduced when speech intelligibility is abolished by presenting speech/noise stimuli in reverse, indicating that linguistic information plays an important role for the observed perceptual entrainment. PMID:25653354

  9. Neural entrainment to rhythmically presented auditory, visual, and audio-visual speech in children.

    PubMed

    Power, Alan James; Mead, Natasha; Barnes, Lisa; Goswami, Usha

    2012-01-01

    Auditory cortical oscillations have been proposed to play an important role in speech perception. It is suggested that the brain may take temporal "samples" of information from the speech stream at different rates, phase resetting ongoing oscillations so that they are aligned with similar frequency bands in the input ("phase locking"). Information from these frequency bands is then bound together for speech perception. To date, there are no explorations of neural phase locking and entrainment to speech input in children. However, it is clear from studies of language acquisition that infants use both visual speech information and auditory speech information in learning. In order to study neural entrainment to speech in typically developing children, we use a rhythmic entrainment paradigm (underlying 2 Hz or delta rate) based on repetition of the syllable "ba," presented in either the auditory modality alone, the visual modality alone, or as auditory-visual speech (via a "talking head"). To ensure attention to the task, children aged 13 years were asked to press a button as fast as possible when the "ba" stimulus violated the rhythm for each stream type. Rhythmic violation depended on delaying the occurrence of a "ba" in the isochronous stream. Neural entrainment was demonstrated for all stream types, and individual differences in standardized measures of language processing were related to auditory entrainment at the theta rate. Further, there was significant modulation of the preferred phase of auditory entrainment in the theta band when visual speech cues were present, indicating cross-modal phase resetting. The rhythmic entrainment paradigm developed here offers a method for exploring individual differences in oscillatory phase locking during development. In particular, a method for assessing neural entrainment and cross-modal phase resetting would be useful for exploring developmental learning difficulties thought to involve temporal sampling, such as

  10. Fusion-Fission Hybrid for Fissile Fuel Production without Processing

    SciTech Connect

    Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

    2012-01-02

    Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in the critical reactors

  11. Process simulation of a PEM fuel cell system

    SciTech Connect

    Ledjeff-Hey, K.; Roes, J.; Formanski, V.; Gieshoff, J.; Vogel, B.

    1996-01-01

    The thermodynamic performance of a PEM fuel cell system for producing electrical power from natural gas is investigated by considering the flows of energy and energy through the various steps of the whole system. The flows of energy are evaluated using a computer code for energy and energy analyses. The fuel cell system is designed to produce a hydrogen volumetric flow of nearly 5.0 m{sup 3} {sub NTP}/h, provided to the fuel cell at an absolute pressure of 2.9 bar. The fuel cell itself is working with an efficiency of about 60 % at an operating temperature of 65 - 75{degrees} C with an air ratio of four and provides a maximum electric power of 9 kW. Taking into consideration only the produced electric power as useful output of the fuel cell system a total efficiency of 42.2 % is calculated using the simulation results.

  12. Fuel Quality/Processing Study. Volume II. Appendix, Task I, literature survey

    SciTech Connect

    O'Hara, J B; Bela, A; Jentz, N E; Klumpe, H W; Kessler, R E; Kotzot, H T; Loran, B I

    1981-04-01

    This activity was begun with the assembly of information from Parsons' files and from contacts in the development and commercial fields. A further more extensive literature search was carried out using the Energy Data Base and the American Petroleum Institute Data Base. These are part of the DOE/RECON system. Approximately 6000 references and abstracts were obtained from the EDB search. These were reviewed and the especially pertinent documents, approximately 300, were acquired in the form of paper copy or microfiche. A Fuel Properties form was developed for listing information pertinent to gas turbine liquid fuel properties specifications. Fuel properties data for liquid fuels from selected synfuel processes, deemed to be successful candidates for near future commercial plants were tabulated on the forms. The processes selected consisted of H-Coal, SRC-II and Exxon Donor Solvent (EDS) coal liquefaction processes plus Paraho and Tosco shale oil processes. Fuel properties analyses for crude and distillate syncrude process products are contained in Section 2. Analyses representing synthetic fuels given refinery treatments, mostly bench scale hydrotreating, are contained in Section 3. Section 4 discusses gas turbine fuel specifications based on petroleum source fuels as developed by the major gas turbine manufacturers. Section 5 presents the on-site gas turbine fuel treatments applicable to petroleum base fuels impurities content in order to prevent adverse contaminant effects. Section 7 relates the environmental aspects of gas turbine fuel usage and combustion performance. It appears that the near future stationary industrial gas turbine fuel market will require that some of the synthetic fuels be refined to the point that they resemble petroleum based fuels.

  13. Heterogeneous catalytic process for alcohol fuels from syngas

    SciTech Connect

    Minahan, D.M.; Nagaki, D.A.

    1995-12-31

    This project is focused on the discovery and evaluation of novel heterogeneous catalyst for the production of oxygenated fuel enhancers from synthesis gas. Catalysts have been studied and optimized for the production of methanol and isobutanol mixtures which may be used for the downstream synthesis of MTBE or related oxygenates. Higher alcohols synthesis (HAS) from syngas was studied; the alcohols that are produced in this process may be used for the downstream synthesis of MTBE or related oxygenates. This work has resulted in the discovery of a catalyst system that is highly selective for isobutanol compared with the prior art. The catalysts operate at high temperature (400{degrees}C), and consist of a spinel oxide support (general formula AB{sub 2}O{sub 4}, where A=M{sup 2+} and B = M{sup 3+}), promoted with various other elements. These catalysts operate by what is believed to be an aldol condensation mechanism, giving a product mix of mainly methanol and isobutanol. In this study, the effect of product feed/recycle (methanol, ethanol. n-propanol, isopropanol, carbon dioxide and water) on the performance of 10-DAN-55 (spinel oxide based catalyst) at 400{degrees}C, 1000 psi, GHSV = 12,000 and syngas (H{sub 2}/CO) ratio = 1:2 (alcohol addition) and 1:1 (carbon dioxide and water addition) was studied. The effect of operation at high temperatures and pressures on the performance of an improved catalyst formulation was also examined.

  14. AFCI Transmutation Fuel Processes and By-Products Planning: Interim Report

    SciTech Connect

    Eric L. Shaber

    2005-09-01

    dictates the need for detailed process flows, mass balances, batch size data, and radiological dose estimates. Full definition of the materials that will need to be handled in the facility as feed material inputs, in-process fuel, scrap recycle, scrap requiring recovery, and by-product wastes is required. The feed material for demonstrating transmutation fuel fabrication will need to come from the separations of actinides from spent nuclear fuel processed in the same AFCF.

  15. Simulation study on factors influencing the entrainment behavior of liquid steel as bubbles pass through the steel/slag interface

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Bao, Yan-ping; Wang, Min; Lin, Lu

    2016-05-01

    In this study, a water/silicone oil interface was used to simulate the steel/slag interface in a converter. A high-speed camera was used to record the entrainment process of droplets when air bubbles were passed through the water/silicone oil interface. Motion parameters of the bubbles and droplets were obtained using particle kinematic analysis software, and the entrainment rate of the droplets was calculated. It was found that the entrainment rate decreased from 29.5% to 0 when the viscosity of the silicone oil was increased from 60 mPa·s to 820 mPa·s in the case of bubbles with a 5 mm equivalent diameter passing through the water/silicone oil interface. The results indicate that increasing the viscosity of the silicone oil is conducive to reducing the entrainment rate. The entrainment rate increased from 0 to 136.3% in the case of silicone oil with a viscosity of 60 mPa·s when the equivalent diameter of the bubbles was increased from 3 mm to 7 mm. We therefore conclude that small bubbles are also conductive to reducing the entrainment rate. The force analysis results for the water column indicate that the entrainment rate of droplets is affected by the velocity of the bubble passing through the water/silicone oil interface and that the entrainment rate decreases with the bubble velocity.

  16. Co-Rolled U10Mo/Zirconium-Barrier-Layer Monolithic Fuel Foil Fabrication Process

    SciTech Connect

    G. A. Moore; M. C. Marshall

    2010-01-01

    Integral to the current UMo fuel foil processing scheme being developed at Idaho National Laboratory (INL) is the incorporation of a zirconium barrier layer for the purpose of controlling UMo-Al interdiffusion at the fuel-meat/cladding interface. A hot “co-rolling” process is employed to establish a ~25-µm-thick zirconium barrier layer on each face of the ~0.3-mm-thick U10Mo fuel foil.

  17. The importance of biotic entrainment for base flow fluvial sediment transport

    NASA Astrophysics Data System (ADS)

    Rice, Stephen P.; Johnson, Matthew F.; Mathers, Kate; Reeds, Jake; Extence, Chris

    2016-05-01

    Sediment transport is regarded as an abiotic process driven by geophysical energy, but zoogeomorphological activity indicates that biological energy can also fuel sediment movements. It is therefore prudent to measure the contribution that biota make to sediment transport, but comparisons of abiotic and biotic sediment fluxes are rare. For a stream in the UK, the contribution of crayfish bioturbation to suspended sediment flux was compared with the amount of sediment moved by hydraulic forcing. During base flow periods, biotic fluxes can be isolated because nocturnal crayfish activity drives diel turbidity cycles, such that nighttime increases above daytime lows are attributable to sediment suspension by crayfish. On average, crayfish bioturbation contributed at least 32% (474 kg) to monthly base flow suspended sediment loads; this biotic surcharge added between 5.1 and 16.1 t (0.21 to 0.66 t km-2 yr-1) to the annual sediment yield. As anticipated, most sediment was moved by hydraulic forcing during floods and the biotic contribution from baseflow periods represented between 0.46 and 1.46% of the annual load. Crayfish activity is nonetheless an important impact during baseflow periods and the measured annual contribution may be a conservative estimate because of unusually prolonged flooding during the measurement period. In addition to direct sediment entrainment by bioturbation, crayfish burrowing supplies sediment to the channel for mobilization during floods so that the total biotic effect of crayfish is potentially greater than documented in this study. These results suggest that in rivers, during base flow periods, bioturbation can entrain significant quantities of fine sediment into suspension with implications for the aquatic ecosystem and base flow sediment fluxes. Energy from life rather than from elevation can make significant contributions to sediment fluxes.

  18. Historic American Engineering Record, Idaho National Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex

    SciTech Connect

    Susan Stacy; Julie Braun

    2006-12-01

    Just as automobiles need fuel to operate, so do nuclear reactors. When fossil fuels such as gasoline are burned to power an automobile, they are consumed immediately and nearly completely in the process. When the fuel is gone, energy production stops. Nuclear reactors are incapable of achieving this near complete burn-up because as the fuel (uranium) that powers them is burned through the process of nuclear fission, a variety of other elements are also created and become intimately associated with the uranium. Because they absorb neutrons, which energize the fission process, these accumulating fission products eventually poison the fuel by stopping the production of energy from it. The fission products may also damage the structural integrity of the fuel elements. Even though the uranium fuel is still present, sometimes in significant quantities, it is unburnable and will not power a reactor unless it is separated from the neutron-absorbing fission products by a method called fuel reprocessing. Construction of the Fuel Reprocessing Complex at the Chem Plant started in 1950 with the Bechtel Corporation serving as construction contractor and American Cyanamid Company as operating contractor. Although the Foster Wheeler Corporation assumed responsibility for the detailed working design of the overall plant, scientists at Oak Ridge designed all of the equipment that would be employed in the uranium separations process. After three years of construction activity and extensive testing, the plant was ready to handle its first load of irradiated fuel.

  19. Automated brush plating process for solid oxide fuel cells

    SciTech Connect

    Long, Jeffrey William

    2003-01-01

    A method of depositing a metal coating (28) on the interconnect (26) of a tubular, hollow fuel cell (10) contains the steps of providing the fuel cell (10) having an exposed interconnect surface (26); contacting the inside of the fuel cell (10) with a cathode (45) without use of any liquid materials; passing electrical current through a contacting applicator (46) which contains a metal electrolyte solution; passing the current from the applicator (46) to the cathode (45) and contacting the interconnect (26) with the applicator (46) and coating all of the exposed interconnect surface.

  20. BIOMASS AND FOSSIL FUEL TO METHANOL AND CARBON VIA THE HYDROCARB PROCESS

    EPA Science Inventory

    The paper discusses the production of methanol and carbon from biomass and fossil fuels, utilizing the Hydrocarbon process. This process has the potential to minimize dependence on imported fuels for the transportation and utility sectors by increasing the yield and reducing the ...

  1. Numerical approach for the voloxidation process of an advanced spent fuel conditioning process (ACP)

    SciTech Connect

    Park, Byung Heung; Jeong, Sang Mun; Seo, Chung-Seok

    2007-07-01

    A voloxidation process is adopted as the first step of an advanced spent fuel conditioning process in order to prepare the SF oxide to be reduced in the following electrolytic reduction process. A semi-batch type voloxidizer was devised to transform a SF pellet into powder. In this work, a simple reactor model was developed for the purpose of correlating a gas phase flow rate with an operation time as a numerical approach. With an assumption that a solid phase and a gas phase are homogeneous in a reactor, a reaction rate for an oxidation was introduced into a mass balance equation. The developed equation can describe a change of an outlet's oxygen concentration including such a case that a gas flow is not sufficient enough to continue a reaction at its maximum reaction rate. (authors)

  2. Isolation of CeLu2 N@Ih -C80 through a Non-Chromatographic, Two-Step Chemical Process and Crystallographic Characterization of the Pyramidalized CeLu2 N within the Icosahedral Cage.

    PubMed

    Stevenson, Steven; Thompson, Hannah R; Arvola, Kristine D; Ghiassi, Kamran B; Olmstead, Marilyn M; Balch, Alan L

    2015-07-13

    By combining two chemical methods of purification, 4 mg of purified CeLu2 N@C80 was readily isolated from 500 mg of carbon soot extract without the use of recycling HPLC, a method which has previously been necessary to obtain pure samples of endohedral fullerenes. In stage 1, CeLu2 N@C80 was selectively precipitated by virtue of its low first oxidation potential (+0.01 V) and the judicious choice of MgCl2 as the Lewis acid precipitant. For stage 2, we used a stir and filter approach (SAFA), which employed the electron-rich NH2 groups immobilized on silica gel to selectively bind residual endohedrals and higher cage fullerenes that were contaminants from stage 1. Crystallographic analysis of CeLu2 N@C80 in the co-crystal CeLu2 N@Ih -C80 ⋅Ni(octaethylporphyrin)⋅2(toluene) reveals that the Ih -C80 cage is present with a pyramidalized CeLu2 N unit inside. PMID:26059441

  3. Fuel Injector With Shear Atomizer

    NASA Technical Reports Server (NTRS)

    Beal, George W.; Mills, Virgil L.; Smith, Durward B., II; Beacom, William F.

    1995-01-01

    Atomizer for injecting liquid fuel into combustion chamber uses impact and swirl to break incoming stream of fuel into small, more combustible droplets. Slanted holes direct flow of liquid fuel to stepped cylindrical wall. Impact on wall atomizes liquid. Air flowing past vanes entrains droplets of liquid in swirling flow. Fuel injected at pressure lower than customarily needed.

  4. Laminar Entrained Flow Reactor (Fact Sheet)

    SciTech Connect

    Not Available

    2014-02-01

    The Laminar Entrained Flow Reactor (LEFR) is a modular, lab scale, single-user reactor for the study of catalytic fast pyrolysis (CFP). This system can be employed to study a variety of reactor conditions for both in situ and ex situ CFP.

  5. LIQUID ENTRAINMENT FROM A MOBILE BED SCRUBBER

    EPA Science Inventory

    The paper gives results of the measurement of liquid entrainment rate and drop size distribution in the exhaust gas stream from a mobile bed scrubber. The pilot plant scrubber was 46 cm square and was packed with 3.8 cm diameter hollow polyethylene spheres to a static depth of 25...

  6. Washing of the AW-101 entrained solids

    SciTech Connect

    GJ Lumetta

    2000-03-31

    BNFL Inc. (BNFL) is under contract with the US Department of Energy, River Protection Project (DOE-RPP) to design, construct, and operate facilities for treating wastes stored in the single-shell and double-shell tanks at the Hanford Site, Richland, Washington. The DOE-BNFL RPP contract identifies two feeds to the waste treatment plant: (1) primarily liquid low-activity waste (LAW) consisting of less than 2 wt% entrained solids and (2) high-level waste (HLW) consisting of 10 to 200 g/L solids slurry. This report describes the results of a test conducted by Battelle to assess the effects of inhibited water washing on the composition of the entrained solids in the diluted AW-101 low-activity waste (LAW) sample. The objective of this work was to gather data on the solubility of the AW-101 entrained solids in 0.01 M NaOH, so that BNFL can evaluate whether these solids require caustic leaching. The work was conducted according to test plan BNFL-TP-29953-9, Rev. 0, LAW Entrained Solids Water Wash and Caustic Leach Testing. The test went according to plan, with no deviations from the test plan. Based on the results of the 0.01 M NaOH washing, a decision was made by BNFL to not proceed with the caustic leaching test. The composition of the washed solids was such that caustic leaching would not result in significant reduction in the immobilized HLW volume.

  7. Attentional entrainment and perceived event duration

    PubMed Central

    McAuley, J. Devin; Fromboluti, Elisa Kim

    2014-01-01

    This study considered the contribution of dynamic attending theory (DAT) and attentional entrainment to systematic distortions in perceived event duration. Three experiments were conducted using an auditory oddball paradigm, in which listeners judged the duration of a deviant (oddball) stimulus embedded within a series of identical (standard) stimuli. To test for a role of attentional entrainment in perceived oddball duration, oddballs were presented at either temporally expected (on time) or unexpectedly early or late time points relative to extrapolation of the context rhythm. Consistent with involvement of attentional entrainment in perceived duration, duration judgements about the oddball were least distorted when the oddball occurred on time with respect to the entrained rhythm, whereas durations of early and late oddballs were perceived to be shorter and longer, respectively. This pattern of results was independent of the absolute time interval preceding the oddball. Moreover, as expected, an irregularly timed sequence context weakened observed differences between oddballs with on-time and late onsets. Combined with other recent work on the role of temporal preparation in duration distortions, the present findings allot at least a portion of the oddball effect to increased attention to events that are more expected, rather than on their unexpected nature per se. PMID:25385779

  8. High temperature air-blown woody biomass gasification model for the estimation of an entrained down-flow gasifier.

    PubMed

    Kobayashi, Nobusuke; Tanaka, Miku; Piao, Guilin; Kobayashi, Jun; Hatano, Shigenobu; Itaya, Yoshinori; Mori, Shigekatsu

    2009-01-01

    A high temperature air-blown gasification model for woody biomass is developed based on an air-blown gasification experiment. A high temperature air-blown gasification experiment on woody biomass in an entrained down-flow gasifier is carried out, and then the simple gasification model is developed based on the experimental results. In the experiment, air-blown gasification is conducted to demonstrate the behavior of this process. Pulverized wood is used as the gasification fuel, which is injected directly into the entrained down-flow gasifier by the pulverized wood banner. The pulverized wood is sieved through 60 mesh and supplied at rates of 19 and 27kg/h. The oxygen-carbon molar ratio (O/C) is employed as the operational condition instead of the air ratio. The maximum temperature achievable is over 1400K when the O/C is from 1.26 to 1.84. The results show that the gas composition is followed by the CO-shift reaction equilibrium. Therefore, the air-blown gasification model is developed based on the CO-shift reaction equilibrium. The simple gasification model agrees well with the experimental results. From calculations in large-scale units, the cold gas is able to achieve 80% efficiency in the air-blown gasification, when the woody biomass feedrate is over 1000kg/h and input air temperature is 700K. PMID:18653324

  9. Fluid-bed fluoride volatility process recovers uranium from spent uranium alloy fuels

    NASA Technical Reports Server (NTRS)

    Barghusen, J. J.; Chilenskas, A. A.; Gunderson, G. E.; Holmes, J. T.; Jonke, A. A.; Kincinas, J. E.; Levitz, N. M.; Potts, G. L.; Ramaswami, D.; Stethers, H.; Turner, K. S.

    1967-01-01

    Fluid-bed fluoride volatility process recovers uranium from uranium fuels containing either zirconium or aluminum. The uranium is recovered as uranium hexafluoride. The process requires few operations in simple, compact equipment, and eliminates aqueous radioactive wastes.

  10. Cloud top entrainment instability and cloud top distributions

    NASA Technical Reports Server (NTRS)

    Boers, Reinout; Spinhirne, James D.

    1990-01-01

    Classical cloud-top entrainment instability condition formulation is discussed. A saturation point diagram is used to investigate the details of mixing in cases where the cloud-top entrainment instability criterion is satisfied.

  11. Features, Events and Processes for the Used Fuel Disposition Campaign

    SciTech Connect

    Blink, J A; Greenberg, H R; Caporuscio, F A; Houseworth, J E; Freeze, G A; Mariner, P; Cunnane, J C

    2010-12-15

    The Used Fuel Disposition (UFD) Campaign within DOE-NE is evaluating storage and disposal options for a range of waste forms and a range of geologic environments. To assess the potential performance of conceptual repository designs for the combinations of waste form and geologic environment, a master set of Features, Events, and Processes (FEPs) has been developed and evaluated. These FEPs are based on prior lists developed by the Yucca Mountain Project (YMP) and the international repository community. The objective of the UFD FEPs activity is to identify and categorize FEPs that are important to disposal system performance for a variety of disposal alternatives (i.e., combinations of waste forms, disposal concepts, and geologic environments). FEP analysis provides guidance for the identification of (1) important considerations in disposal system design, and (2) gaps in the technical bases. The UFD FEPs also support the development of performance assessment (PA) models to evaluate the long-term performance of waste forms in the engineered and geologic environments of candidate disposal system alternatives. For the UFD FEP development, five waste form groups and seven geologic settings are being considered. A total of 208 FEPs have been identified, categorized by the physical components of the waste disposal system as well as cross-cutting physical phenomena. The combination of 35 waste-form/geologic environments and 208 FEPs is large; however, some FEP evaluations can cut across multiple waste/environment combinations, and other FEPs can be categorized as not-applicable for some waste/environment combinations, making the task of FEP evaluation more tractable. A FEP status tool has been developed to document progress. The tool emphasizes three major areas that can be statused numerically. FEP Applicability documents whether the FEP is pertinent to a waste/environment combination. FEP Completion Status documents the progress of the evaluation for the FEP

  12. Preparation and characterization of Ce0.8Y0.2-xCuxO2-δ as electrolyte for intermediate temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Ji, Bifa; Tian, Changan; Wang, Chunyang; Wu, Tong; Xie, Jinsong; Li, Minghua

    2015-03-01

    In this study, ultrafine Ce0.8Y0.2-xCuxO2-δ (for x = 0.00, 0.04, 0.08, 0.12, 0.16, 0.20) powders have been successfully prepared by sol-gel auto-combustion method. The samples were characterized by FTIR, TG-DSC, XRD, Raman spectroscopy, BET, TEM, SEM, AC impedance, and thermal expansion measurements. The results indicated that Ce0.8Y0.2-xCuxO2-δ powders with highly phase-pure cubic fluorite-type structure were obtained after calcining at 700 °C for 2 h; the average crystallite sizes were between 11.3 and 17.9 nm. The as-synthesized powders exhibited high sintering activity, Ce0.8Y0.2-xCuxO2-δ series electrolytes which have higher relatively dense over 95% can obtain after sintering at 1300 °C for 4 h Ce0.8Y0.12Cu0.08O1.86 electrolyte sintered at 1300 °C for 4 h exhibits the highest oxide ionic conductivity (σ800 °C = 0.029 S cm-1), lowest electrical activation energy (Ea = 0.75 eV) and moderate thermal expansion coefficient (TEC = 13.5 × 10-6 K-1, between 25 and 800 °C). Therefore, it was concluded that co-doping with appropriate ratio of Y/Cu can further improve the properties of ceria electrolytes.

  13. H2S removal with ZnO during fuel processing for PEM fuel cell applications

    SciTech Connect

    Li, Liyu; King, David L.

    2006-09-15

    The possibility of using ZnO as a H2S absorbent to protect catalysts in the gasoline and diesel fuel processor for PEM fuel cell applications was studied. It is possible to use commercial ZnO absorbent as a guard bed to protect the PROX catalyst and PEM fuel cell. However, it is not feasible to use ZnO to protect high and low temperature WGS catalysts, most likely due to COS formation via reactions CO + H2S = COS + H2 and CO2 + H2S = COS + H2O.

  14. Sensitivity analysis of a dry-processed Candu fuel pellet's design parameters

    SciTech Connect

    Choi, Hangbok; Ryu, Ho Jin

    2007-07-01

    Sensitivity analysis was carried out in order to investigate the effect of a fuel pellet's design parameters on the performance of a dry-processed Canada deuterium uranium (CANDU) fuel and to suggest the optimum design modifications. Under a normal operating condition, a dry-processed fuel has a higher internal pressure and plastic strain due to a higher fuel centerline temperature when compared with a standard natural uranium CANDU fuel. Under a condition that the fuel bundle dimensions do not change, sensitivity calculations were performed on a fuel's design parameters such as the axial gap, dish depth, gap clearance and plenum volume. The results showed that the internal pressure and plastic strain of the cladding were most effectively reduced if a fuel's element plenum volume was increased. More specifically, the internal pressure and plastic strain of the dry-processed fuel satisfied the design limits of a standard CANDU fuel when the plenum volume was increased by one half a pellet, 0.5 mm{sup 3}/K. (authors)

  15. Development of a model of entrained flow coal gasification and study of aerodynamic mechanisms of action on gasifier operation

    NASA Astrophysics Data System (ADS)

    Abaimov, N. A.; Ryzhkov, A. F.

    2015-11-01

    Problems requiring solution in development of modern highly efficient gasification reactor of a promising high power integrated gasification combined-cycle plant are formulated. The task of creating and testing a numerical model of an entrained-flow reactor for thermochemical conversion of pulverized coal is solved. The basic method of investigation is computational fluid dynamics. The submodel of thermochemical processes, including a single-stage scheme of volatile substances outlet and three heterogeneous reactions of carbon residue conversion (complete carbon oxidation, Boudouard reaction and hydrogasification), is given. The mass loss rate is determined according to the basic assumptions of the diffusion-kinetic theory. The equations applied for calculation of the process of outlet of volatile substances and three stages of fuel gasifi-cation (diffusion of reagent gas toward the surface of the coal particle, heterogeneous reactions of gas with carbon on its surface, and homogeneous reactions beyond the particle surface) are presented. The universal combined submodel Eddy Dissipation/Finite Rate Chemistry with standard (built-in) constants is used for numerical estimates. Aerodynamic mechanisms of action on thermochemical processes of solid fuel gasification are studied, as exemplified by the design upgrade of a cyclone reactor of preliminary thermal fuel preparation. Volume concentrations of combustible gases and products of complete combustion in the syngas before and after primary air and pulverized coal flows' redistribution are given. Volume concentrations of CO in syngas at different positions of tangential secondary air inlet nozzle are compared.

  16. Properties of Aluminum Deposited by a High-Velocity Oxygen-Fueled Process

    SciTech Connect

    Chow, R; Decker, T A; Gansert, R V; Gansert, D; Lee, D

    2001-06-12

    Aluminum coatings deposited by a HVOF process have been demonstrated and relevant coating properties evaluated according to two deposition parameters, the spray distance and the oxygen-to-fuel flow ratio. The coating porosity, surface roughness, and microhardness are measured. The coating properties are fairly insensitive to spray distance, the distance between the nozzle and the workpiece, and fuel ratios, the oxygen-to-fuel flow. Increasing the fuel content does appear to improve the process productivity in terms of surface roughness. Minimization of nozzle loading is discussed.

  17. ENTRAINMENT BY LIGAMENT-CONTROLLED EFFERVESCENT ATOMIZER-PRODUCED SPRAYS

    EPA Science Inventory

    Entrainment of ambient air into sprays produced by a new type of effervescent atomizer is reported. Entrainment data were obtained using a device similar to that described by Ricou & Spalding (1961). Entrainment data were analyzed using the model of Bush & Sojka (1994), in concer...

  18. A facile synthesis of high quality nanostructured CeO2 and Gd2O3-doped CeO2 solid electrolytes for improved electrochemical performance.

    PubMed

    Kuo, Yu-Lin; Su, Yu-Ming; Chou, Hung-Lung

    2015-06-01

    This study describes the use of a composite nitrate salt solution as a precursor to synthesize CeO2 and Gd2O3-doped CeO2 (GDC) nanoparticles (NPs) using an atmospheric pressure plasma jet (APPJ). The microstructures of CeO2 and GDC NPs were found to be cubical and spherical shaped nanocrystallites with average particle sizes of 10.5 and 6.7 nm, respectively. Reactive oxygen species, detected by optical emission spectroscopy (OES), are believed to be the major oxidative agents for the formation of oxide materials in the APPJ process. Based on the material characterization and OES observations, the study effectively demonstrated the feasibility of preparing well-crystallized GDC NPs by the APPJ system as well as the gas-to-particle mechanism. Notably, the Bader charge of CeO2 and Ce0.9Gd0.1O2 characterized by density function theory (DFT) simulation and AC impedance measurements shows that Gd helps in increasing the charge on Ce0.9Gd0.1O2 NPs, thus improving their conductivity and making them candidate materials for electrolytes in solid oxide fuel cells. PMID:25959436

  19. Technical and economic feasibility of alternative fuel use in process heaters and small boilers

    SciTech Connect

    Not Available

    1980-02-01

    The technical and economic feasibility of using alternate fuels - fuels other than oil and natural gas - in combustors not regulated by the Powerplant and Industrial Fuel Use Act of 1978 (FUA) was evaluated. FUA requires coal or alternate fuel use in most large new boilers and in some existing boilers. Section 747 of FUA authorizes a study of the potential for reduced oil and gas use in combustors not subject to the act: small industrial boilers with capacities less than 100 MMBtu/hr, and process heat applications. Alternative fuel use in combustors not regulated by FUA was examined and the impact of several measures to encourage the substitution of alternative fuels in these combustors was analyzed. The primary processes in which significant fuel savings can be achieved are identified. Since feedstock uses of oil and natural gas are considered raw materials, not fuels, feedstock applications are not examined in this analysis. The combustors evaluated in this study comprise approximately 45% of the fuel demand projected in 1990. These uses would account for more than 3.5 million barrels per day equivalent fuel demand in 1990.

  20. Apparatus for entrained coal pyrolysis

    DOEpatents

    Durai-Swamy, Kandaswamy

    1982-11-16

    This invention discloses a process and apparatus for pyrolyzing particulate coal by heating with a particulate solid heating media in a transport reactor. The invention tends to dampen fluctuations in the flow of heating media upstream of the pyrolysis zone, and by so doing forms a substantially continuous and substantially uniform annular column of heating media flowing downwardly along the inside diameter of the reactor. The invention is particularly useful for bituminous or agglomerative type coals.

  1. Entrained gasification combined-cycle control study. Volume 3: model descriptions. Final report

    SciTech Connect

    Clark, J.; Denton, L.; Hashemi, M.; Joiner, J.; Smelser, S.; Chowaniec, C.; Hobbs, M.; Jennings, S.; Phelts, E.

    1980-07-01

    Two control strategies were evaluated for a new type of electric power plant as part of a large utility network. An entrained coal gasifier fuels a gas turbine/steam turbine combined-cycle unit forming the integrated plant which was simulated by computer to analyze alternative control strategies. Transient operation of this gasification-combined-cycle (GCC) plant was studied to determine open-loop response as a stand-alone plant, as well as closed-loop response while functioning in a typical utility power system. GCC plant performance during specified operating contingencies, such as equipment trip or emergency shutdown, was also studied. This volume presents the model descriptions for the Texaco entrained gasifiers, Selexol unit, oxygen plant, scrubber, ammonia absorber, water balance, combustion turbine-generator and gas-turbine controls, heat recovery steam generators, steam turbine-generator and steam-turbine controls, fuel gas expander, power system, and station controller.

  2. Literature on fabrication of tungsten for application in pyrochemical processing of spent nuclear fuels

    SciTech Connect

    Edstrom, C.M.; Phillips, A.G.; Johnson, L.D.; Corle, R.R.

    1980-10-11

    The pyrochemical processing of nuclear fuels requires crucibles, stirrers, and transfer tubing that will withstand the temperature and the chemical attack from molten salts and metals used in the process. This report summarizes the literature that pertains to fabrication (joining, chemical vapor deposition, plasma spraying, forming, and spinning) is the main theme. This report also summarizes a sampling of literature on molbdenum and the work previously performed at Argonne National Laboratory on other container materials used for pyrochemical processing of spent nuclear fuels.

  3. Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

    DOEpatents

    Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

    2016-07-05

    The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

  4. Flowsheet for shear/leach processing of N Reactor fuel at PUREX

    SciTech Connect

    Enghusen, M.B.

    1995-04-13

    This document was originally prepared to support the restart of the PUREX plant using a new Shear/Leach head end process. However, the PUREX facility was shutdown and processing of the remaining N Reactor fuel is no longer considered an alternative for fuel disposition. This document is being issued for reference only to document the activities which were investigated to incorporate the shear/leach process in the PUREX plant.

  5. Processing of FRG mixed oxide fuel elements at General Atomic under the US/FRG cooperative agreement for spent fuel elements

    SciTech Connect

    Holder, N.D.; Strand, J.B.; Schwarz, F.A.; Tischer, H.E.

    1980-11-01

    The Federal Republic of Germany (FRG) and the United States (US) are cooperating on certain aspects gas-cooled reactor technology under an umbrella agreement. Under the spent fuel treatment section of the agreement, FRG fuel spheres were recently sent for processing in the Department of Energy sponsored cold pilot plant for High-Temperature Gas-Cooled Reactor (HTGR) fuel processing at General Atomic Company in San Diego, California. The FRG fuel spheres were crushed and burned to recover coated fuel particles. These particles were in turn crushed and burned to recover the fuel-bearing kernels for further treatment for uranium recovery. Successful completion of the tests described in this paper demonstrated the applicability of the US HTGR fuel treatment flowsheet to FRG fuel processing. 10 figures.

  6. Processing of FRG high-temperature gas-cooled reactor fuel elements at General Atomic under the US/FRG cooperative agreement for spent fuel elements

    SciTech Connect

    Holder, N.D.; Strand, J.B.; Schwarz, F.A.; Drake, R.N.

    1981-11-01

    The Federal Republic of Germany (FRG) and the United States (US) are cooperating on certain aspects of gas-cooled reactor technology under an umbrella agreement. Under the spent fuel treatment development section of the agreement, both FRG mixed uranium/ thorium and low-enriched uranium fuel spheres have been processed in the Department of Energy-sponsored cold pilot plant for high-temperature gas-cooled reactor (HTGR) fuel processing at General Atomic Company in San Diego, California. The FRG fuel spheres were crushed and burned to recover coated fuel particles suitable for further treatment for uranium recovery. Successful completion of the tests described in this paper demonstrated certain modifications to the US HTGR fuel burining process necessary for FRG fuel treatment. Results of the tests will be used in the design of a US/FRG joint prototype headend facility for HTGR fuel.

  7. Process technologies for production of fuel ethanol from lignocellulosic biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignocellulosic biomass such as corn stover, wheat straw, rice straw, and switchgrass can serve as low-cost feedstock for production of fuel ethanol. These feedstocks contain complex carbohydrates (cellulose and hemicelluloses) which need to be converted to fermentable sugars and then these sugars b...

  8. COAL PROCESSING TECHNOLOGY: ENVIRONMENTAL IMPACT OF SYNTHETIC FUELS DEVELOPMENT

    EPA Science Inventory

    This paper describes a portion of a comprehensive, long term EPA program to evaluate the environmental effects of energy systems that produce gaseous and liquid fuels from coal. The technologies being assessed include low-, medium-, and high-Btu gasification and liquefaction. One...

  9. Energy and exergy analysis of an ethanol reforming process for solid oxide fuel cell applications.

    PubMed

    Tippawan, Phanicha; Arpornwichanop, Amornchai

    2014-04-01

    The fuel processor in which hydrogen is produced from fuels is an important unit in a fuel cell system. The aim of this study is to apply a thermodynamic concept to identify a suitable reforming process for an ethanol-fueled solid oxide fuel cell (SOFC). Three different reforming technologies, i.e., steam reforming, partial oxidation and autothermal reforming, are considered. The first and second laws of thermodynamics are employed to determine an energy demand and to describe how efficiently the energy is supplied to the reforming process. Effect of key operating parameters on the distribution of reforming products, such as H2, CO, CO2 and CH4, and the possibility of carbon formation in different ethanol reformings are examined as a function of steam-to-ethanol ratio, oxygen-to-ethanol ratio and temperatures at atmospheric pressure. Energy and exergy analysis are performed to identify the best ethanol reforming process for SOFC applications. PMID:24561628

  10. Droplet entrainment correlation for high pressure annular two-phase flow

    SciTech Connect

    Lopez de Betodano, M.A.; Jan, Cheng-Shiun; Beus, S.G.

    1996-01-01

    The amount of entrainment in annular flow is essential to predict the point of dryout. Most of the entrainment correlations available in the literature are obtained from air-water low pressure data. However many important industrial applications involve high pressure annular flows. There are very few correlations applicable in this range and they are solely based on empirical data fits. Comparing the low pressure entrainment data of Cousins and Hewitt (1968) and the high pressure data of Keeys et. al. (1970) and Wurtz (1978) with existing correlations, the agreement at high pressure is generally poor, except for the empirical correlation of Nigmatulin and Krushenok (1989) which depends on a Weber number that includes the droplet concentration. We propose a new semi-mechanistic entrainment correlation for fully developed annular flow conditions: E = (0.9642)/(1 + (3836/We{sub C})). It is developed based on the droplet continuity equation and the entrainment rate model of Dallman et. al. (1979). This model is then modified to introduce a Weber number that includes the droplet concentration, We{sub C}. This Weber number is shown to scale the available high and low pressure air-water and steam-water data better than the other definitions. Because the new correlation is based on a model of entrainment rate it may be used as a starting point in the development of a correlation for this process applicable to high pressure water-steam annular flows. A correlation is suggested pending validation with high pressure entrainment rate data. 12 refs., 11 figs.

  11. Influence of a platinum functional layer on a Ni-Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} anode for thin-film solid oxide fuel cells

    SciTech Connect

    Kang, Sungmin; Cha, Suk Won E-mail: swcha@snu.ac.kr; Chang, Ikwhang; Kim, Young-Beom E-mail: swcha@snu.ac.kr

    2015-09-15

    A Pt functional layer was deposited between a Ni-Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} (50 wt. % Ni) anode and an 8 mol. % yttria-stabilized zirconia electrolyte in order to enhance the performance of a thin film solid oxide fuel cell. By inserting this ultrathin functional layer, the ohmic impedance of the single cell was significantly reduced, and the maximum power density was increased by a factor of ∼1.55. However, excessive deposition of the Pt functional layer caused ionic conduction pathway blocking between the yttria-stabilized zirconia and Ni-Gd{sub 0.1}Ce{sub 0.9}O{sub 1.95} (Ni-GDC), deactivating the Ni-GDC as a mixed ionic and electronic conducting anode. As a result, both the ohmic impedance and anodic faradaic impedance were increased after introduction of excessive Pt functional layer, and the maximum power density was also reduced.

  12. Synthesis, characterization and mechanical properties of NiO - GDC20 (Ce0.8Gd0.2O1.9) nano composite anode for solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Reddy, M. Narsimha; Rao, P. Vijaya Bhaskar; Sharma, R. K.

    2016-05-01

    In the present research work, X (NiO) +1-X(Ce0.8Gd0.2O1.9) where X = 30,40 and 45 wt% Nano Composite Anodes are synthesized for low temperature operating solid oxide fuel cells (SOFC). NiO and Ce0.8Gd0.2O1.9 (GDC20) are synthesized by sol-gel citrate method and the nanopowders of NiO, GDC20 were calcined from 650 °c to 750 °c. For anode materials, pelletized the nanocomposites of X(NiO)+ (1-X) GDC20 (X = 30,40,45 wt.%) and sintered at 1200 °c. systematic study of atomic structure, purity, phase and structural parameters such as Lattice parameters, crystallite size of as-synthesized nanopowders and anode materials were carried out by XRD and SEM. For mechanical strength, Vickers micro-hardness of anode composites were estimated and observed that micro-hardness of composites were increasing with NiO wt.% and the density of sintered samples, which is varying from 4.35 to 5.54 Gpa at 500g load.

  13. Enhanced sinterability and conductivity of BaZr0.3Ce0.5Y0.2O3-δ by addition of bismuth oxide for proton conducting solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Gui, Liangqi; Ling, Yihan; Li, Geng; Wang, Zhihao; Wan, Yanhong; Wang, Ranran; He, Beibei; Zhao, Ling

    2016-01-01

    The effect of bismuth oxide addition on the sintering behavior and electrical properties of BaZr0.3Ce0.5Y0.2O3-δ (BZCY) as an electrolyte for proton conducting solid oxide fuel cells (H-SOFCs) is studied. The introduction of Bi2O3 is beneficial to improving sinterability of BZCY, resulting in high density. Meanwhile, the conductivity test indicates that BaZr0.3Ce0.5Y0.2O3-δ - 2 mol% Bi2O3 (BZCY-2) promises the highest conductivities. Further, single cells with BZCY-2 as the electrolyte are fabricated and evaluated. The cell with BZCY-2 presents excellent power densities, which reaches 0.67, 0.44, and 0.27 mW cm-2 at 700, 650, and 600 °C, respectively. The conductivities of BZCY-2 film are higher than BZCY in this work and other reported BZCY films. The encouraging results suggest that the addition of a small amount (2 mol%) of Bi2O3 to BZCY can significantly promote sinterability and electrical conductivity for H-SOFCs.

  14. CHEMICALLY ACTIVE FLUID BED PROCESS FOR SULPHUR REMOVAL DURING GASIFICATION OF CARBONACEOUS FUELS

    EPA Science Inventory

    The report covers the final 3 years of a 9-year program to evaluate the Chemically Active Fluid Bed (CAFB) process for gasification and desulfurization of liquid and solid fuels in a fluidized bed of hot lime. A range of alternative fuels, including three coals and a lignite, wer...

  15. SYSTEM AND PROCESS FOR PRODUCTION OF METHANOL FROM COMBINED WIND TURBINE AND FUEL CELL POWER

    EPA Science Inventory

    The paper examines an integrated use of ultra-clean wind turbines and high temperature fuel cells to produce methanol, especially for transportation purposes. The principal utility and application of the process is the production of transportation fuel from domestic resources to ...

  16. AW-101 entrained solids - Solubility versus temperature

    SciTech Connect

    GJ Lumetta; RC Lettau; GF Piepel

    2000-03-31

    This report describes the results of a test conducted by Battelle to assess the solubility of the solids entrained in the diluted AW-101 low-activity waste (LAW) sample. BNFL requested Battelle to dilute the AW-1-1 sample using de-ionized water to mimic expected plant operating conditions. BNFL further requested Battelle to assess the solubility of the solids present in the diluted AW-101 sample versus temperature conditions of 30, 40, and 50 C. BNFL requested these tests to assess the composition of the LAW supernatant and solids versus expected plant-operating conditions. The work was conducted according to test plan BNFL-TP-29953-7, Rev. 0, Determination of the Solubility of LAW Entrained Solids. The test went according to plan, with no deviations from the test plan.

  17. Alignment strategies for the entrainment of music and movement rhythms.

    PubMed

    Moens, Bart; Leman, Marc

    2015-03-01

    Theories of entrainment assume that spontaneous entrainment emerges from dynamic laws that operate via mediators on interactions, whereby entrainment is facilitated if certain conditions are fulfilled. In this study, we show that mediators can be built that affect the entrainment of human locomotion to music. More specifically, we built D-Jogger, a music player that functions as a mediator between music and locomotion rhythms. The D-Jogger makes it possible to manipulate the timing differences between salient moments of the rhythms (beats and footfalls) through the manipulation of the musical period and phase, which affect the condition in which entrainment functions. We conducted several experiments to explore different strategies for manipulating the entrainment of locomotion and music. The results of these experiments showed that spontaneous entrainment can be manipulated, thereby suggesting different strategies on how to embark. The findings furthermore suggest a distinction among different modalities of entrainment: finding the beat (the most difficult part of entrainment), keeping the beat (easier, as a temporal scheme has been established), and being in phase (no entrainment is needed because the music is always adapted to the human rhythm). This study points to a new avenue of research on entrainment and opens new perspectives for the neuroscience of music. PMID:25773621

  18. Auditory-motor entrainment in vocal mimicking species

    PubMed Central

    2010-01-01

    We have recently found robust evidence of motor entrainment to auditory stimuli in multiple species of non-human animal, all of which were capable of vocal mimicry. In contrast, the ability remained markedly absent in many closely related species incapable of vocal mimicry. This suggests that vocal mimicry may be a necessary precondition for entrainment. However, within the vocal mimicking species, entrainment appeared non-randomly, suggesting that other components besides vocal mimicry play a role in the capacity and tendency to entrain. Here we discuss potential additional factors involved in entrainment. New survey data show that both male and female parrots are able to entrain, and that the entrainment capacity appears throughout the lifespan. We suggest routes for future study of entrainment, including both developmental studies in species known to entrain and further work to detect entrainment in species not well represented in our dataset. These studies may shed light on additional factors necessary for entrainment in addition to vocal mimicry. PMID:20714417

  19. Systems Analysis of an Advanced Nuclear Fuel Cycle Based on a Modified UREX+3c Process

    SciTech Connect

    E. R. Johnson; R. E. Best

    2009-12-28

    The research described in this report was performed under a grant from the U.S. Department of Energy (DOE) to describe and compare the merits of two advanced alternative nuclear fuel cycles -- named by this study as the “UREX+3c fuel cycle” and the “Alternative Fuel Cycle” (AFC). Both fuel cycles were assumed to support 100 1,000 MWe light water reactor (LWR) nuclear power plants operating over the period 2020 through 2100, and the fast reactors (FRs) necessary to burn the plutonium and minor actinides generated by the LWRs. Reprocessing in both fuel cycles is assumed to be based on the UREX+3c process reported in earlier work by the DOE. Conceptually, the UREX+3c process provides nearly complete separation of the various components of spent nuclear fuel in order to enable recycle of reusable nuclear materials, and the storage, conversion, transmutation and/or disposal of other recovered components. Output of the process contains substantially all of the plutonium, which is recovered as a 5:1 uranium/plutonium mixture, in order to discourage plutonium diversion. Mixed oxide (MOX) fuel for recycle in LWRs is made using this 5:1 U/Pu mixture plus appropriate makeup uranium. A second process output contains all of the recovered uranium except the uranium in the 5:1 U/Pu mixture. The several other process outputs are various waste streams, including a stream of minor actinides that are stored until they are consumed in future FRs. For this study, the UREX+3c fuel cycle is assumed to recycle only the 5:1 U/Pu mixture to be used in LWR MOX fuel and to use depleted uranium (tails) for the makeup uranium. This fuel cycle is assumed not to use the recovered uranium output stream but to discard it instead. On the other hand, the AFC is assumed to recycle both the 5:1 U/Pu mixture and all of the recovered uranium. In this case, the recovered uranium is reenriched with the level of enrichment being determined by the amount of recovered plutonium and the combined amount

  20. 10 CFR 140.13a - Amount of financial protection required for plutonium processing and fuel fabrication plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... plutonium processing and fuel fabrication plant is required to have and maintain financial protection in the... use plutonium at two or more plutonium processing and fuel fabrication plants at the same location... protection covers all such plants at the location....

  1. 10 CFR 140.13a - Amount of financial protection required for plutonium processing and fuel fabrication plants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... plutonium processing and fuel fabrication plant is required to have and maintain financial protection in the... use plutonium at two or more plutonium processing and fuel fabrication plants at the same location... protection covers all such plants at the location....

  2. 10 CFR 140.13a - Amount of financial protection required for plutonium processing and fuel fabrication plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... plutonium processing and fuel fabrication plant is required to have and maintain financial protection in the... use plutonium at two or more plutonium processing and fuel fabrication plants at the same location... protection covers all such plants at the location....

  3. SAF: the next generation process for radiotoxic material handling in the nuclear fuel industry

    SciTech Connect

    Nyman, D.H.; Graham, R.A.

    1984-07-19

    In 1980 the Secure Automated Fabrication (SAF) Project was established with the goal to design, build, and operate a remote process for manufacturing breeder reactor fuel pins. The SAF line will be housed in the Fuels and Materials Examination Facility (FMEF) at the Hanford site. The fabrication system and supporting operations are designed for computer-controlled operation from a centralized control room. In addition to improved worker protection, remote and automated fuel fabrication operations will result in enhanced safeguards and accountability of fuel material, improved product quality, and increased productivity. Installation of the SAF line equipment has started. Qualification runs are scheduled to begin in 1986 with production commencing in 1987.

  4. Fuel-Flexible Combustion System for Refinery and Chemical Plant Process Heaters

    SciTech Connect

    2010-06-01

    Funded by the American Recovery and Reinvestment Act of 2009 ENVIRON International Corporation, in collaboration with Callidus Technologies by Honeywell and Shell Global Solutions, Inc., will develop and demonstrate a full-scale fuel blending and combustion system. This system will allow a broad range of opportunity fuel compositions, including syngas, biogas, natural gas, and refinery fuel gas, to be safely, cost-effectively, and efficiently utilized while generating minimal emissions of criteria pollutants. The project will develop a commercial technology for application in refinery and chemical plant process heaters where opportunity fuels are used.

  5. Development of Hot Pressing as a Low Cost Processing Technique for Fuel Cell Fabrication

    SciTech Connect

    Sarin, V

    2003-01-14

    Dependable, plentiful, and economical energy has been the driving force for financial, industrial, and political growth in the US since the mid 19th century. For a country whose progress is so deeply rooted in abundant energy and whose current political agenda involves stabilizing world fossil fuel prices, the development of a reliable, efficient and environmentally friendly power generating source seems compulsory. The maturing of high technology fuel cells may be the panacea the country will find indispensable to free itself from foreign dependence. Fuel cells offer an efficient, combustion-less, virtually pollution-free power source, capable of being sited in downtown urban areas or in remote regions. Fuel cells have few moving parts and run almost silently. Fuel cells are electrochemical devices that convert the chemical energy of a fuel directly to electrical energy. Unlike batteries, which store a finite amount of energy, fuel cells will generate electricity continuously, as long as fuel and oxidant are available to the electrodes. Additionally, fuel cells offer clean, efficient, and reliable power and they can be operated using a variety of fuels. Hence, the fuel cell is an extremely promising technology. Over the course of this research, the fundamental knowledge related to ceramic processing, sintering, and hot pressing to successfully hot press a single operational SOFC in one step has been developed. Ceramic powder processing for each of the components of an SOFC has bene tailored towards this goal. Processing parameter for the electrolyte and cathode have been studied and developed until they converted. Several anode fabrication techniques have been developed. Additionally, a novel anode structured has been developed and refined. These individual processes have been cultivated until a single cell SOFC has been fabricated in one step.

  6. Rod Driven Frequency Entrainment and Resonance Phenomena.

    PubMed

    Salchow, Christina; Strohmeier, Daniel; Klee, Sascha; Jannek, Dunja; Schiecke, Karin; Witte, Herbert; Nehorai, Arye; Haueisen, Jens

    2016-01-01

    A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α) of each volunteer in the range from 0.40 to 2.30(∗)α. Three hundred and six-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90-1.10(∗)α) and half of the alpha frequency (0.40-0.55(∗)α). No signs of resonance and frequency entrainment phenomena were revealed around 2.00(∗)α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30-2.30(∗)α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex. PMID:27588002

  7. Rod Driven Frequency Entrainment and Resonance Phenomena

    PubMed Central

    Salchow, Christina; Strohmeier, Daniel; Klee, Sascha; Jannek, Dunja; Schiecke, Karin; Witte, Herbert; Nehorai, Arye; Haueisen, Jens

    2016-01-01

    A controversy exists on photic driving in the human visual cortex evoked by intermittent photic stimulation. Frequency entrainment and resonance phenomena are reported for frequencies higher than 12 Hz in some studies while missing in others. We hypothesized that this might be due to different experimental conditions, since both high and low intensity light stimulation were used. However, most studies do not report radiometric measurements, which makes it impossible to categorize the stimulation according to photopic, mesopic, and scotopic vision. Low intensity light stimulation might lead to scotopic vision, where rod perception dominates. In this study, we investigated photic driving for rod-dominated visual input under scotopic conditions. Twelve healthy volunteers were stimulated with low intensity light flashes at 20 stimulation frequencies, leading to rod activation only. The frequencies were multiples of the individual alpha frequency (α) of each volunteer in the range from 0.40 to 2.30∗α. Three hundred and six-channel whole head magnetoencephalography recordings were analyzed in time, frequency, and spatiotemporal domains with the Topographic Matching Pursuit algorithm. We found resonance phenomena and frequency entrainment for stimulations at or close to the individual alpha frequency (0.90–1.10∗α) and half of the alpha frequency (0.40–0.55∗α). No signs of resonance and frequency entrainment phenomena were revealed around 2.00∗α. Instead, on-responses at the beginning and off-responses at the end of each stimulation train were observed for the first time in a photic driving experiment at frequencies of 1.30–2.30∗α, indicating that the flicker fusion threshold was reached. All results, the resonance and entrainment as well as the fusion effects, provide evidence for rod-dominated photic driving in the visual cortex. PMID:27588002

  8. New insights into the wind-dust relationship in sandblasting and direct aerodynamic entrainment from wind tunnel experiments

    NASA Astrophysics Data System (ADS)

    Parajuli, Sagar Prasad; Zobeck, Ted M.; Kocurek, Gary; Yang, Zong-Liang; Stenchikov, Georgiy L.

    2016-02-01

    Numerous parameterizations have been developed for predicting wind erosion, yet the physical mechanism of dust emission is not fully understood. Sandblasting is thought to be the primary mechanism, but recent studies suggest that dust emission by direct aerodynamic entrainment can be significant under certain conditions. In this work, using wind tunnel experiments, we investigated some of the lesser understood aspects of dust emission in sandblasting and aerodynamic entrainment for three soil types, namely, clay, silty clay loam, and clay loam. First, we explored the role of erodible surface roughness on dust emitted by aerodynamic entrainment. Second, we compared the emitted dust concentration in sandblasting and aerodynamic entrainment under a range of wind friction velocities. Finally, we explored the sensitivity of emitted dust particle size distribution (PSD) to soil type and wind friction velocity in these two processes. The dust concentration in aerodynamic entrainment showed strong positive correlation, no significant correlation, and weak negative correlation, for the clay, silty clay loam, and clay loam, respectively, with the erodible soil surface roughness. The dust in aerodynamic entrainment was significant constituting up to 28.3, 41.4, and 146.4% compared to sandblasting for the clay, silty clay loam, and clay loam, respectively. PSD of emitted dust was sensitive to soil type in both sandblasting and aerodynamic entrainment. PSD was sensitive to the friction velocity in aerodynamic entrainment but not in sandblasting. Our results highlight the need to consider the details of sandblasting and direct aerodynamic entrainment processes in parameterizing dust emission in global/regional climate models.

  9. Controllability of plutonium concentration for FBR fuel at a solvent extraction process in the PUREX process

    SciTech Connect

    Enokida, Youichi; Kitano, Motoki; Sawada, Kayo

    2013-07-01

    Typical Purex solvent extraction systems for the reprocessing of spent nuclear fuel have a feed material containing dilute, 1% in weight, plutonium, along with uranium and fission products. Current reprocessing proposals call for no separation of the pure plutonium. The work described in this paper studied, by computer simulation, the fundamental feasibility of preparing a 20% concentrated plutonium product solution from the 1% feed by adjusting only the feed rates and acid concentrations of the incoming streams and without the addition of redox reagents for the plutonium. A set of process design flowsheets has been developed to realize a concentrated plutonium solution of a 20% stream from the dilute plutonium feed without using redox reagents. (authors)

  10. 40 CFR 80.1416 - Petition process for evaluation of new renewable fuels pathways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... make it, and the production process. The justification must include process modeling flow charts. (iii... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Petition process for evaluation of new... Petition process for evaluation of new renewable fuels pathways. (a) Pursuant to this section, a party...

  11. Diurnally entrained anticipatory behavior in archaea.

    PubMed

    Whitehead, Kenia; Pan, Min; Masumura, Ken-ichi; Bonneau, Richard; Baliga, Nitin S

    2009-01-01

    By sensing changes in one or few environmental factors biological systems can anticipate future changes in multiple factors over a wide range of time scales (daily to seasonal). This anticipatory behavior is important to the fitness of diverse species, and in context of the diurnal cycle it is overall typical of eukaryotes and some photoautotrophic bacteria but is yet to be observed in archaea. Here, we report the first observation of light-dark (LD)-entrained diurnal oscillatory transcription in up to 12% of all genes of a halophilic archaeon Halobacterium salinarum NRC-1. Significantly, the diurnally entrained transcription was observed under constant darkness after removal of the LD stimulus (free-running rhythms). The memory of diurnal entrainment was also associated with the synchronization of oxic and anoxic physiologies to the LD cycle. Our results suggest that under nutrient limited conditions halophilic archaea take advantage of the causal influence of sunlight (via temperature) on O(2) diffusivity in a closed hypersaline environment to streamline their physiology and operate oxically during nighttime and anoxically during daytime. PMID:19424498

  12. Disposal of defense spent fuel and HLW from the Idaho Chemical Processing Plant

    SciTech Connect

    Ermold, L.F.; Loo, H.H.; Klingler, R.D.; Herzog, J.D.; Knecht, D.A.

    1992-12-01

    Acid high-level radioactive waste (HLW) resulting from fuel reprocessing at the Idaho Chemical Processing Plant (ICPP) for the US Department of Energy (DOE) has been solidified to a calcine since 1963 and stored in stainless steel bins enclosed by concrete vaults. Several different types of unprocessed irradiated DOE-owned fuels are also in storage ate the ICPP. In April, 1992, DOE announced that spent fuel would no longer be reprocessed to recover enriched uranium and called for a shutdown of the reprocessing facilities at the ICPP. A new Spent Fuel and HLW Technology Development program was subsequently initiated to develop technologies for immobilizing ICPP spent fuels and HLW for disposal, in accordance with the Nuclear Waste Policy Act. The Program elements include Systems Analysis, Graphite Fuel Disposal, Other Spent Fuel Disposal, Sodium-Bearing Liquid Waste Processing, Calcine Immobilization, and Metal Recycle/Waste Minimization. This paper presents an overview of the ICPP radioactive wastes and current spent fuels, with an emphasis on the description of HLW and spent fuels requiring repository disposal.

  13. Analysis of irradiated U-7wt%Mo dispersion fuel microstructures using automated image processing

    DOE PAGESBeta

    Collette, R.; King, J.; Buesch, C.; Keiser, Jr., D. D.; Williams, W.; Miller, B. D.; Schulthess, J.

    2016-04-01

    The High Performance Research Reactor Fuel Development (HPPRFD) program is responsible for developing low enriched uranium (LEU) fuel substitutes for high performance reactors fueled with highly enriched uranium (HEU) that have not yet been converted to LEU. The uranium-molybdenum (U-Mo) fuel system was selected for this effort. In this study, fission gas pore segmentation was performed on U-7wt%Mo dispersion fuel samples at three separate fission densities using an automated image processing interface developed in MATLAB. Pore size distributions were attained that showed both expected and unexpected fission gas behavior. In general, it proved challenging to identify any dominant trends whenmore » comparing fission bubble data across samples from different fuel plates due to varying compositions and fabrication techniques. Here, the results exhibited fair agreement with the fission density vs. porosity correlation developed by the Russian reactor conversion program.« less

  14. Analysis of irradiated U-7wt%Mo dispersion fuel microstructures using automated image processing

    NASA Astrophysics Data System (ADS)

    Collette, R.; King, J.; Buesch, C.; Keiser, D. D.; Williams, W.; Miller, B. D.; Schulthess, J.

    2016-07-01

    The High Performance Research Reactor Fuel Development (HPPRFD) program is responsible for developing low enriched uranium (LEU) fuel substitutes for high performance reactors fueled with highly enriched uranium (HEU) that have not yet been converted to LEU. The uranium-molybdenum (U-Mo) fuel system was selected for this effort. In this study, fission gas pore segmentation was performed on U-7wt%Mo dispersion fuel samples at three separate fission densities using an automated image processing interface developed in MATLAB. Pore size distributions were attained that showed both expected and unexpected fission gas behavior. In general, it proved challenging to identify any dominant trends when comparing fission bubble data across samples from different fuel plates due to varying compositions and fabrication techniques. The results exhibited fair agreement with the fission density vs. porosity correlation developed by the Russian reactor conversion program.

  15. Spent Nuclear Fuel (SNF) Process Validation Technical Support Plan

    SciTech Connect

    SEXTON, R.A.

    2000-05-09

    The purpose of Process Validation is to confirm that nominal process operations are consistent with the expected process envelope. The Process Validation activities described in this document are not part of the safety basis, but are expected to demonstrate that the process operates well within the safety basis. Some adjustments to the process may be made as a result of information gathered in Process Validation.

  16. Electrical start-up for diesel fuel processing in a fuel-cell-based auxiliary power unit

    NASA Astrophysics Data System (ADS)

    Samsun, Remzi Can; Krupp, Carsten; Tschauder, Andreas; Peters, Ralf; Stolten, Detlef

    2016-01-01

    As auxiliary power units in trucks and aircraft, fuel cell systems with a diesel and kerosene reforming capacity offer the dual benefit of reduced emissions and fuel consumption. In order to be commercially viable, these systems require a quick start-up time with low energy input. In pursuit of this end, this paper reports an electrical start-up strategy for diesel fuel processing. A transient computational fluid dynamics model is developed to optimize the start-up procedure of the fuel processor in the 28 kWth power class. The temperature trend observed in the experiments is reproducible to a high degree of accuracy using a dual-cell approach in ANSYS Fluent. Starting from a basic strategy, different options are considered for accelerating system start-up. The start-up time is reduced from 22 min in the basic case to 9.5 min, at an energy consumption of 0.4 kW h. Furthermore, an electrical wire is installed in the reformer to test the steam generation during start-up. The experimental results reveal that the generation of steam at 450 °C is possible within seconds after water addition to the reformer. As a result, the fuel processor can be started in autothermal reformer mode using the electrical concept developed in this work.

  17. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    NASA Astrophysics Data System (ADS)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-11-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

  18. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    NASA Technical Reports Server (NTRS)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-01-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

  19. Word-by-word entrainment of speech rhythm during joint story building

    PubMed Central

    Himberg, Tommi; Hirvenkari, Lotta; Mandel, Anne; Hari, Riitta

    2015-01-01

    Movements and behavior synchronize during social interaction at many levels, often unintentionally. During smooth conversation, for example, participants adapt to each others' speech rates. Here we aimed to find out to which extent speakers adapt their turn-taking rhythms during a story-building game. Nine sex-matched dyads of adults (12 males, 6 females) created two 5-min stories by contributing to them alternatingly one word at a time. The participants were located in different rooms, with audio connection during one story and audiovisual during the other. They were free to select the topic of the story. Although the participants received no instructions regarding the timing of the story building, their word rhythms were highly entrained (øverlineR = 0.70, p < 0.001) even though the rhythms as such were unstable (øverlineR = 0.14 for pooled data). Such high entrainment in the absence of steady word rhythm occurred in every individual story, independently of whether the subjects were connected via audio-only or audiovisual link. The observed entrainment was of similar strength as typical entrainment in finger-tapping tasks where participants are specifically instructed to synchronize their behavior. Thus, speech seems to spontaneously induce strong entrainment between the conversation partners, likely reflecting automatic alignment of their semantic and syntactic processes. PMID:26124735

  20. Getting the beat: entrainment of brain activity by musical rhythm and pleasantness.

    PubMed

    Trost, Wiebke; Frühholz, Sascha; Schön, Daniele; Labbé, Carolina; Pichon, Swann; Grandjean, Didier; Vuilleumier, Patrik

    2014-12-01

    Rhythmic entrainment is an important component of emotion induction by music, but brain circuits recruited during spontaneous entrainment of attention by music and the influence of the subjective emotional feelings evoked by music remain still largely unresolved. In this study we used fMRI to test whether the metric structure of music entrains brain activity and how music pleasantness influences such entrainment. Participants listened to piano music while performing a speeded visuomotor detection task in which targets appeared time-locked to either strong or weak beats. Each musical piece was presented in both a consonant/pleasant and dissonant/unpleasant version. Consonant music facilitated target detection and targets presented synchronously with strong beats were detected faster. FMRI showed increased activation of bilateral caudate nucleus when responding on strong beats, whereas consonance enhanced activity in attentional networks. Meter and consonance selectively interacted in the caudate nucleus, with greater meter effects during dissonant than consonant music. These results reveal that the basal ganglia, involved both in emotion and rhythm processing, critically contribute to rhythmic entrainment of subcortical brain circuits by music. PMID:25224999

  1. Passive scalar entrainment and mixing in a forced, spatially-developing mixing layer

    NASA Technical Reports Server (NTRS)

    Lowery, P. S.; Reynolds, W. C.; Mansour, N. N.

    1987-01-01

    Numerical simulations are performed for the forced, spatially-developing plane mixing layer in two and three dimensions. Transport of a passive scalar field is included in the computation. This, together with the allowance for spatial development in the simulations, affords the opportunity for study of the asymmetric entrainment of irrotational fluid into the layer. The inclusion of a passive scalar field provides a means for simulating the effect of this entrainment asymmetry on the generation of 'products' from a 'fast' chemical reaction. Further, the three-dimensional simulations provide useful insight into the effect of streamwise structures on these entrainment and 'fast' reaction processes. Results from a two-dimensional simulation indicate 1.22 parts high-speed fluid are entrained for every one part low-speed fluid. Inclusion of streamwise vortices at the inlet plane of a three-dimensional simulation indicate a further increase in asymmetric entrainment - 1.44:1. Results from a final three-dimensional simulation are presented. In this case, a random velocity perturbation is imposed at the inlet plane. The results indicate the 'natural' development of the large spanwise structures characteristic of the mixing layer.

  2. Structure study of BaCe0.85Y0.15O3-Δ as solid state fuel cell material

    NASA Astrophysics Data System (ADS)

    Krezhov, K.; Vladikova, D.; Raikova, G.; Genov, I.; Malakova, T.; Dimitrov, D.; Svab, E.; Fabian, M.

    2016-03-01

    The structural details of powder, dense and porous samples of BaCe0.85Y0.15O3-δ (BCY15) used recently in an innovative monolithic design of SOFC were studied from multiple Rietveld analysis of neutron and x-ray diffraction patterns. The 3-layered monolithic assembly built from BCY15 material works as oxide ion conductor in the oxygen space, as proton conductor in the hydrogen area and as mixed conductor in the central membrane. We find that in all the samples of studied BCY15 based materials there are no indications of difference in crystallographic symmetry and the structure refinements did produce best agreement factors in orthorhombic Pnma space group.

  3. TRISO-Coated Fuel Processing to Support High Temperature Gas-Cooled Reactors

    SciTech Connect

    Del Cul, G.D.

    2002-10-01

    The initial objective of the work described herein was to identify potential methods and technologies needed to disassemble and dissolve graphite-encapsulated, ceramic-coated gas-cooled-reactor spent fuels so that the oxide fuel components can be separated by means of chemical processing. The purpose of this processing is to recover (1) unburned fuel for recycle, (2) long-lived actinides and fission products for transmutation, and (3) other fission products for disposal in acceptable waste forms. Follow-on objectives were to identify and select the most promising candidate flow sheets for experimental evaluation and demonstration and to address the needs to reduce technical risks of the selected technologies. High-temperature gas-cooled reactors (HTGRs) may be deployed in the next -20 years to (1) enable the use of highly efficient gas turbines for producing electricity and (2) provide high-temperature process heat for use in chemical processes, such as the production of hydrogen for use as clean-burning transportation fuel. Also, HTGR fuels are capable of significantly higher burn-up than light-water-reactor (LWR) fuels or fast-reactor (FR) fuels; thus, the HTGR fuels can be used efficiently for transmutation of fissile materials and long-lived actinides and fission products, thereby reducing the inventory of such hazardous and proliferation-prone materials. The ''deep-burn'' concept, described in this report, is an example of this capability. Processing of spent graphite-encapsulated, ceramic-coated fuels presents challenges different from those of processing spent LWR fuels. LWR fuels are processed commercially in Europe and Japan; however, similar infrastructure is not available for processing of the HTGR fuels. Laboratory studies on the processing of HTGR fuels were performed in the United States in the 1960s and 1970s, but no engineering-scale processes were demonstrated. Currently, new regulations concerning emissions will impact the technologies used in

  4. Solid recovered fuel: influence of waste stream composition and processing on chlorine content and fuel quality.

    PubMed

    Velis, Costas; Wagland, Stuart; Longhurst, Phil; Robson, Bryce; Sinfield, Keith; Wise, Stephen; Pollard, Simon

    2012-02-01

    Solid recovered fuel (SRF) produced by mechanical-biological treatment (MBT) of municipal waste can replace fossil fuels, being a CO(2)-neutral, affordable, and alternative energy source. SRF application is limited by low confidence in quality. We present results for key SRF properties centered on the issue of chlorine content. A detailed investigation involved sampling, statistical analysis, reconstruction of composition, and modeling of SRF properties. The total chlorine median for a typical plant during summer operation was 0.69% w/w(d), with lower/upper 95% confidence intervals of 0.60% w/w(d) and 0.74% w/w(d) (class 3 of CEN Cl indicator). The average total chlorine can be simulated, using a reconciled SRF composition before shredding to <40 mm. The relative plastics vs paper mass ratios in particular result in an SRF with a 95% upper confidence limit for ash content marginally below the 20% w/w(d) deemed suitable for certain power plants; and a lower 95% confidence limit of net calorific value (NCV) at 14.5 MJ kg(ar)(-1). The data provide, for the first time, a high level of confidence on the effects of SRF composition on its chlorine content, illustrating interrelationships with other fuel properties. The findings presented here allow rational debate on achievable vs desirable MBT-derived SRF quality, informing the development of realistic SRF quality specifications, through modeling exercises, needed for effective thermal recovery. PMID:22191490

  5. The Importance of Stochastic Effects for Explaining Entrainment in the Zebrafish Circadian Clock

    PubMed Central

    Heussen, Raphaela; Whitmore, David

    2015-01-01

    The circadian clock plays a pivotal role in modulating physiological processes and has been implicated, either directly or indirectly, in a range of pathological states including cancer. Here we investigate how the circadian clock is entrained by external cues such as light. Working with zebrafish cell lines and combining light pulse experiments with simulation efforts focused on the role of synchronization effects, we find that even very modest doses of light exposure are sufficient to trigger some entrainment, whereby a higher light intensity or duration correlates with strength of the circadian signal. Moreover, we observe in the simulations that stochastic effects may be considered an essential feature of the circadian clock in order to explain the circadian signal decay in prolonged darkness, as well as light initiated resynchronization as a strong component of entrainment. PMID:26649069

  6. Debris entrainment and landform genesis during tidewater glacier surges

    NASA Astrophysics Data System (ADS)

    Lovell, Harold; Fleming, Edward J.; Benn, Douglas I.; Hubbard, Bryn; Lukas, Sven; Rea, Brice R.; Noormets, Riko; Flink, Anne E.

    2015-08-01

    The englacial entrainment of basal debris during surges presents an opportunity to investigate processes acting at the glacier bed. The subsequent melt-out of debris-rich englacial structures during the quiescent phase produces geometrical ridge networks on glacier forelands that are diagnostic of surge activity. We investigate the link between debris entrainment and proglacial geomorphology by analyzing basal ice, englacial structures, and ridge networks exposed at the margins of Tunabreen, a tidewater surge-type glacier in Svalbard. The basal ice facies display clear evidence for brittle and ductile tectonic deformation, resulting in overall thickening of the basal ice sequence. The formation of debris-poor dispersed facies ice is the result of strain-induced metamorphism of meteoric ice near the bed. Debris-rich englacial structures display a variety of characteristics and morphologies and are interpreted to represent the incorporation and elevation of subglacial till via the squeezing of till into basal crevasses and hydrofracture exploitation of thrust faults, reoriented crevasse squeezes, and preexisting fractures. These structures are observed to melt-out and form embryonic geometrical ridge networks at the base of a terrestrially grounded ice cliff. Ridge networks are also located at the terrestrial margins of Tunabreen, neighboring Von Postbreen, and in a submarine position within Tempelfjorden. Analysis of network characteristics allows these ridges to be linked to different formational mechanisms of their parent debris-rich englacial structures. This in turn provides an insight into variations in the dominant tectonic stress regimes acting across the glacier during surges.

  7. Development and control of the process for the manufacture of zircaloy-4 tubing for LWBR fuel rods

    SciTech Connect

    Eyler, J.H.

    1981-01-01

    The technical requirements for the Light Water Breeder Reactor (LWBR) fuel elements (fuel rods) imposed certain unique requirements for the low hafnium Zircaloy-4 tubing used as fuel rod cladding. This report describes, in detail, the tube manufacturing process, the product and process controls used, the inspections and tests performed, and the efforts involved in refining a commercial tube reducing process to produce tubes that would satisfy the requirements for LWBR fuel rod cladding.

  8. Hydrodeoxygenation processes: advances on catalytic transformations of biomass-derived platform chemicals into hydrocarbon fuels.

    PubMed

    De, Sudipta; Saha, Basudeb; Luque, Rafael

    2015-02-01

    Lignocellulosic biomass provides an attractive source of renewable carbon that can be sustainably converted into chemicals and fuels. Hydrodeoxygenation (HDO) processes have recently received considerable attention to upgrade biomass-derived feedstocks into liquid transportation fuels. The selection and design of HDO catalysts plays an important role to determine the success of the process. This review has been aimed to emphasize recent developments on HDO catalysts in effective transformations of biomass-derived platform molecules into hydrocarbon fuels with reduced oxygen content and improved H/C ratios. Liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenation, hydrogenolysis, decarbonylation etc.) as well as by increasing the molecular weight via C-C coupling reactions (e.g. aldol condensation, ketonization, oligomerization, hydroxyalkylation etc.). Fundamentals and mechanistic aspects of the use of HDO catalysts in deoxygenation reactions will also be discussed. PMID:25443804

  9. Progress on matrix SiC processing and properties for fully ceramic microencapsulated fuel form

    NASA Astrophysics Data System (ADS)

    Terrani, K. A.; Kiggans, J. O.; Silva, C. M.; Shih, C.; Katoh, Y.; Snead, L. L.

    2015-02-01

    The consolidation mechanism and resulting properties of the silicon carbide (SiC) matrix of fully ceramic microencapsulated (FCM) fuel form are discussed. The matrix is produced via the nano-infiltration transient eutectic-forming (NITE) process. Coefficient of thermal expansion, thermal conductivity, and strength characteristics of this SiC matrix have been characterized in the unirradiated state. An ad hoc methodology for estimation of thermal conductivity of the neutron-irradiated NITE-SiC matrix is also provided to aid fuel performance modeling efforts specific to this concept. Finally, specific processing methods developed for production of an optimal and reliable fuel form using this process are summarized. These various sections collectively report the progress made to date on production of optimal FCM fuel form to enable its application in light water and advanced reactors.

  10. Conduit entrainment surrounding sinking metal-silicate plumes during core formation

    NASA Astrophysics Data System (ADS)

    Klein, S. M.; Brand, D.; Weeraratne, D. S.

    2014-12-01

    Although the Earth today is segregated into two distinct compositional regions of a silicate mantle and metallic core, the process of differentiation from their original chondritic form is not clear. Continuous meteorite bombardment melted impactors and target bodies causing dissociation of metal from silicates which may have formed magma reservoirs or oceans. The heavy liquid metal phase will sink quickly through a silicate magma ocean and settle at the base as a metal pond. A high density metal pond will be unstable and is expected to sink as a Rayleigh-Taylor instability descending as liquid metal plumes to the core. Previous experiments have shown that lighter silicate material from the magma ocean becomes entrained as a conduit that trails behind sinking metal diapirs. These silicates are then transported to the base of the mantle with implications for mantle and core composition. We perform laboratory fluid experiments which model this process of entrainment and differentiation using glass and gallium spheres in high viscosity liquid sucrose solutions. We use high speed photography and dye to visualize and measure conduit formation and entrainment surrounding a descending sphere. Preliminary experiments indicate that the volume of material that surrounds a sphere is highest at the top of the box when the sphere begins its descent. As the sphere sinks, the entrainment of dyed fluid around the sphere decreases exponentially with falling distance. We suggest this is the result of drag forces acting on walls of the conduit. The volume of entrained material reduces by 80% in the upper 1/3 of the drop trajectory. As much as 8-10% of the original fluid volume is carried to the base of the box and will segregate from the sphere or diffuse after it settles. Higher viscosity fluids are observed to entrain more material on average compared to lower viscosity fluids. These results have important implications for delivery of silicate materials to the base of the mantle

  11. Endogenous Delta/Theta Sound-Brain Phase Entrainment Accelerates the Buildup of Auditory Streaming.

    PubMed

    Riecke, Lars; Sack, Alexander T; Schroeder, Charles E

    2015-12-21

    In many natural listening situations, meaningful sounds (e.g., speech) fluctuate in slow rhythms among other sounds. When a slow rhythmic auditory stream is selectively attended, endogenous delta (1‒4 Hz) oscillations in auditory cortex may shift their timing so that higher-excitability neuronal phases become aligned with salient events in that stream [1, 2]. As a consequence of this stream-brain phase entrainment [3], these events are processed and perceived more readily than temporally non-overlapping events [4-11], essentially enhancing the neural segregation between the attended stream and temporally noncoherent streams [12]. Stream-brain phase entrainment is robust to acoustic interference [13-20] provided that target stream-evoked rhythmic activity can be segregated from noncoherent activity evoked by other sounds [21], a process that usually builds up over time [22-27]. However, it has remained unclear whether stream-brain phase entrainment functionally contributes to this buildup of rhythmic streams or whether it is merely an epiphenomenon of it. Here, we addressed this issue directly by experimentally manipulating endogenous stream-brain phase entrainment in human auditory cortex with non-invasive transcranial alternating current stimulation (TACS) [28-30]. We assessed the consequences of these manipulations on the perceptual buildup of the target stream (the time required to recognize its presence in a noisy background), using behavioral measures in 20 healthy listeners performing a naturalistic listening task. Experimentally induced cyclic 4-Hz variations in stream-brain phase entrainment reliably caused a cyclic 4-Hz pattern in perceptual buildup time. Our findings demonstrate that strong endogenous delta/theta stream-brain phase entrainment accelerates the perceptual emergence of task-relevant rhythmic streams in noisy environments. PMID:26628008

  12. Assessment of sulfur removal processes for advanced fuel cell systems

    NASA Astrophysics Data System (ADS)

    Lorton, G. A.

    1980-01-01

    The performance characteristics of potential sulfur removal processes were evaluated and four of these processes, the Selexol process, the Benfield process, the Sulfinol process, and the Rectisol process, were selected for detailed technical and economic comparison. The process designs were based on a consistent set of technical criteria for a grass roots facility with a capacity of 10,000 tons per day of Illinois No. 6 coal. Two raw gas compositions, based on oxygen blown and air blown Texaco gasification, were used. The bulk of the sulfur was removed in the sulfur removal unit, leaving a small amount of sulfur compounds in the gas. The remaining sulfur compounds were removed by reaction with zinc oxide in the sulfur polishing unit. The impact of COS hydrolysis pretreatment on sulfur removal was evaluated. Comprehensive capital and O and M cost estimates for each of the process schemes were developed.

  13. Multiphase CFD-based models for chemical looping combustion process: Fuel reactor modeling

    SciTech Connect

    Jung, Jonghwun; Gamwo, I.K.

    2008-04-21

    Chemical looping combustion (CLC) is a flameless two-step fuel combustion that produces a pure CO2 stream, ready for compression and sequestration. The process is composed of two interconnected fluidized bed reactors. The air reactor which is a conventional circulating fluidized bed and the fuel reactor which is a bubbling fluidized bed. The basic principle is to avoid the direct contact of air and fuel during the combustion by introducing a highly-reactive metal particle, referred to as oxygen carrier, to transport oxygen from the air to the fuel. In the process, the products from combustion are kept separated from the rest of the flue gases namely nitrogen and excess oxygen. This process eliminates the energy intensive step to separate the CO2 from nitrogen-rich flue gas that reduce the thermal efficiency. Fundamental knowledge of multiphase reactive fluid dynamic behavior of the gas–solid flow is essential for the optimization and operation of a chemical looping combustor. Our recent thorough literature review shows that multiphase CFD-based models have not been adapted to chemical looping combustion processes in the open literature. In this study, we have developed the reaction kinetics model of the fuel reactor and implemented the kinetic model into a multiphase hydrodynamic model, MFIX, developed earlier at the National Energy Technology Laboratory. Simulated fuel reactor flows revealed high weight fraction of unburned methane fuel in the flue gas along with CO2 and H2O. This behavior implies high fuel loss at the exit of the reactor and indicates the necessity to increase the residence time, say by decreasing the fuel flow rate, or to recirculate the unburned methane after condensing and removing CO2.

  14. Coal fueled ported kiln direct reduction process in Norway

    SciTech Connect

    Rierson, D.W.

    1994-12-31

    Allis Mineral Systems (AMS), formerly the minerals processing group at Allis-Chalmers Corporation, developed a ported kiln process in the 1960`s specifically for the direct reduction of iron ore. The process is called ACCAR. This ported kiln technology has more recently been coupled with AMS` GRATE-KILN System for iron oxide pelletizing into the GRATE-CAR Process, for minerals reduction. The GRATE-CAR Process can handle a fine grained ore concentrate through the steps of agglomeration, induration and reduction in a single production line.

  15. Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process.

    PubMed

    Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M; Sabir, Suhail; Khan, Mohammad Zain

    2015-01-01

    Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5-8.0, 27(±2°C and 10.6-18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery. PMID:26496083

  16. Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process

    PubMed Central

    Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M.; Sabir, Suhail; Khan, Mohammad Zain

    2015-01-01

    Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5–8.0, 27(±2°C and 10.6–18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery. PMID:26496083

  17. The ecology of entrainment: Foundations of coordinated rhythmic movement

    PubMed Central

    Phillips-Silver, Jessica; Aktipis, C. Athena; Bryant, Gregory A.

    2011-01-01

    Entrainment has been studied in a variety of contexts including music perception, dance, verbal communication and motor coordination more generally. Here we seek to provide a unifying framework that incorporates the key aspects of entrainment as it has been studied in these varying domains. We propose that there are a number of types of entrainment that build upon pre-existing adaptations that allow organisms to perceive stimuli as rhythmic, to produce periodic stimuli, and to integrate the two using sensory feedback. We suggest that social entrainment is a special case of spatiotemporal coordination where the rhythmic signal originates from another individual. We use this framework to understand the function and evolutionary basis for coordinated rhythmic movement and to explore questions about the nature of entrainment in music and dance. The framework of entrainment presented here has a number of implications for the vocal learning hypothesis and other proposals for the evolution of coordinated rhythmic behavior across an array of species. PMID:21776183

  18. ENTRAINMENT, DEPOSITION, AND TRANSPORT OF FINE-GRAINED SEDIMENTS IN LAKES

    EPA Science Inventory

    Recent work on the settling, diffusion, entrainment, and deposition of fine-grained sediments in fresh water is reviewed and synthesized in the report. Particular attention is given to the dependence of these processes on sediment properties such as particle size. The application...

  19. Simulation of primary fuel atomization processes at subcritical pressures.

    SciTech Connect

    Arienti, Marco

    2013-06-01

    This report documents results from an LDRD project for the first-principles simulation of the early stages of spray formation (primary atomization). The first part describes a Cartesian embedded-wall method for the calculation of flow internal to a real injector in a fully coupled primary calculation. The second part describes the extension to an all-velocity formulation by introducing a momentum-conservative semi-Lagrangian advection and by adding a compressible term in the Poisson's equation. Accompanying the description of the new algorithms are verification tests for simple two-phase problems in the presence of a solid interface; a validation study for a scaled-up multi-hole Diesel injector; and demonstration calculations for the closing and opening transients of a single-hole injector and for the high-pressure injection of liquid fuel at supersonic velocity.

  20. AN-107 entrained solids - Solubility versus temperature

    SciTech Connect

    GJ Lumetta; RC Lettau

    2000-03-31

    This report describes the results of a test conducted by Battelle to assess the solubility of the solids entrained in the diluted AN-107 low-activity waste (LAW) sample. BNFL requested Battelle to dilute the AN-107 sample using sodium hydroxide and de-ionized water to mimic expected plant operating conditions. BNFL further requested Battelle to assess the solubility of the solids present in the diluted AN-107 sample versus temperature conditions of 30, 40, and 50 C. BNFL requested these tests to assess the composition of the LAW supernatant and solids versus expected plant-operating conditions.

  1. Increasing jet entrainment, mixing and spreading

    DOEpatents

    Farrington, Robert B.

    1994-01-01

    A free jet of air is disturbed at a frequency that substantially matches natural turbulences in the free jet to increase the entrainment, mixing, and spreading of air by the free jet, for example in a room or other enclosure. The disturbances are created by pulsing the flow of air that creates the free jet at the desired frequency. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.

  2. Increasing jet entrainment, mixing and spreading

    DOEpatents

    Farrington, R.B.

    1994-08-16

    A free jet of air is disturbed at a frequency that substantially matches natural turbulences in the free jet to increase the entrainment, mixing, and spreading of air by the free jet, for example in a room or other enclosure. The disturbances are created by pulsing the flow of air that creates the free jet at the desired frequency. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct. 11 figs.

  3. Entrainment and mixing in thrust augmenting ejectors

    NASA Technical Reports Server (NTRS)

    Bernal, L.; Sarohia, V.

    1983-01-01

    An experimental investigation of two-dimensional thrust augmenting ejector flows has been conducted. Measurements of the shroud surface pressure distribution, mean velocity, turbulent intensities and Reynolds stresses were made in two shroud geometries at various primary nozzle pressure ratios. The effects of shroud geometry and primary nozzle pressure ratio on the shroud surface pressure distribution, mean flow field and turbulent field were determined. From these measurements the evolution of mixing within the shroud of the primary flow and entrained fluid was obtained. The relationship between the mean flow field, the turbulent field and the shroud surface pressure distribution is discussed.

  4. On-line ultrasonic gas entrainment monitor

    DOEpatents

    Day, Clifford K.; Pedersen, Herbert N.

    1978-01-01

    Apparatus employing ultrasonic energy for detecting and measuring the quantity of gas bubbles present in liquids being transported through pipes. An ultrasonic transducer is positioned along the longitudinal axis of a fluid duct, oriented to transmit acoustic energy radially of the duct around the circumference of the enclosure walls. The back-reflected energy is received centrally of the duct and interpreted as a measure of gas entrainment. One specific embodiment employs a conical reflector to direct the transmitted acoustic energy radially of the duct and redirect the reflected energy back to the transducer for reception. A modified embodiment employs a cylindrical ultrasonic transducer for this purpose.

  5. Processing used nuclear fuel with nanoscale control of uranium and ultrafiltration

    NASA Astrophysics Data System (ADS)

    Wylie, Ernest M.; Peruski, Kathryn M.; Prizio, Sarah E.; Bridges, Andrea N. A.; Rudisill, Tracy S.; Hobbs, David T.; Phillip, William A.; Burns, Peter C.

    2016-05-01

    Current separation and purification technologies utilized in the nuclear fuel cycle rely primarily on liquid-liquid extraction and ion-exchange processes. Here, we report a laboratory-scale aqueous process that demonstrates nanoscale control for the recovery of uranium from simulated used nuclear fuel (SIMFUEL). The selective, hydrogen peroxide induced oxidative dissolution of SIMFUEL material results in the rapid assembly of persistent uranyl peroxide nanocluster species that can be separated and recovered at moderate to high yield from other process-soluble constituents using sequestration-assisted ultrafiltration. Implementation of size-selective physical processes like filtration could results in an overall simplification of nuclear fuel cycle technology, improving the environmental consequences of nuclear energy and reducing costs of processing.

  6. Cathodoluminescence degradation of SiO{sub 2}:Ce,Tb powder phosphors prepared by a sol-gel process

    SciTech Connect

    Ntwaeaborwa, O. M.; Swart, H. C.; Kroon, R. E.; Botha, J. R.; Holloway, P. H.

    2007-07-15

    Auger electron spectroscopy (AES), cathodoluminescence (CL) spectroscopy, and x-ray photoelectron spectroscopy (XPS) were used to study the CL intensity degradation of SiO{sub 2}:Cb,Tb powder phosphors prepared by a sol-gel process. The AES and the CL data were collected simultaneously when the powders were bombarded for 10 h with a beam of electrons of current density of 54 mA/cm{sup 2}, accelerated by 2 kV in a vacuum chamber containing either 1x10{sup -8} or 1x10{sup -7} Torr O{sub 2}. A decrease of CL intensity was simultaneous with desorption of oxygen (O) from the surface, i.e., there is a correlation between the degradation of CL intensity and desorption of O. The AES and the XPS data suggest that a nonluminescent oxygen-deficient layer of SiO{sub x} (x<2) that could decrease the CL intensity was formed on the surface. Mechanisms by which oxygen desorption leads to a reduction of the CL intensity are discussed.

  7. Aerosol entrainment from a sparged non-Newtonian slurry.

    PubMed

    Fritz, Brad G

    2006-08-01

    Previous bench-scale experiments have provided data necessary for the development of empirical models that describe aerosol entrainment from bubble bursting. However, previous work has not been extended to non-Newtonian liquid slurries. Design of a waste treatment plant on the Hanford Site in Washington required an evaluation of the applicability of these models outside of their intended range. For this evaluation, aerosol measurements were conducted above an air-sparged mixing tank filled with simulated waste slurry possessing Bingham plastic rheological properties. Three aerosol-size fractions were measured at three sampling heights and for three different sparging rates. The measured entrainment was compared with entrainment models. One model developed based on bench-scale air-water experiments agreed well with measured entrainment. Another model did not agree well with the measured entrainment. It appeared that the source of discrepancy between measured and modeled entrainment stemmed from application beyond the range of data used to develop the model. A possible separation in entrainment coefficients between air-water and steam-water systems was identified. A third entrainment model was adapted to match experimental conditions and fit a posteri to the experimental data, resulting in a modified version that resulted in estimated entrainment rates similar to the first model. PMID:16933643

  8. An observational study of entrainment rate in deep convection

    SciTech Connect

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Zhang, Guang Jun; Liu, Yangang

    2015-09-22

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal, gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. The entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.

  9. An observational study of entrainment rate in deep convection

    DOE PAGESBeta

    Guo, Xiaohao; Lu, Chunsong; Zhao, Tianliang; Zhang, Guang Jun; Liu, Yangang

    2015-09-22

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal,more » gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. The entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.« less

  10. Comparison of entrainment rates from a tank experiment with results using the one-dimensional turbulence model.

    SciTech Connect

    Kerstein, Alan R.; Sayler, B. J.; Wunsch, S.; Schmidt, H.; Nedelec, R.

    2010-05-01

    Recent work suggests that cloud effects remain one of the largest sources of uncertainty in model-based estimates of climate sensitivity. In particular, the entrainment rate in stratocumulus-topped mixed layers needs better models. More than thirty years ago a clever laboratory experiment was conducted by McEwan and Paltridge to examine an analog of the entrainment process at the top of stratiform clouds. Sayler and Breidenthal extended this pioneering work and determined the effect of the Richardson number on the dimensionless entrainment rate. The experiments gave hints that the interaction between molecular effects and the one-sided turbulence seems to be crucial for understanding entrainment. From the numerical point of view large-eddy simulation (LES) does not allow explicitly resolving all the fine scale processes at the entrainment interface. Direct numerical simulation (DNS) is limited due to the Reynolds number and is not the tool of choice for parameter studies. Therefore it is useful to investigate new modeling strategies, such as stochastic turbulence models which allow sufficient resolution at least in one dimension while having acceptable run times. We will present results of the One-Dimensional Turbulence stochastic simulation model applied to the experimental setup of Sayler and Breidenthal. The results on radiatively induced entrainment follow quite well the scaling of the entrainment rate with the Richardson number that was experimentally found for a set of trials. Moreover, we investigate the influence of molecular effects, the fluids optical properties, and the artifact of parasitic turbulence experimentally observed in the laminar layer. In the simulations the parameters are varied systematically for even larger ranges than in the experiment. Based on the obtained results a more complex parameterization of the entrainment rate than currently discussed in the literature seems to be necessary.

  11. Dissolution process for ZrO.sub.2 -UO.sub.2 -CaO fuels

    DOEpatents

    Paige, Bernice E.

    1976-06-22

    The present invention provides an improved dissolution process for ZrO.sub.2 -UO.sub.2 -CaO-type pressurized water reactor fuels. The zirconium cladding is dissolved with hydrofluoric acid, immersing the ZrO.sub.2 -UO.sub.2 -CaO fuel wafers in the resulting zirconium-dissolver-product in the dissolver vessel, and nitric acid is added to the dissolver vessel to facilitate dissolution of the uranium from the ZrO.sub.2 -UO.sub.2 -CaO fuel wafers.

  12. Activity of fuel batches processed through Hanford separations plants, 1944 through 1989

    SciTech Connect

    Watrous, R.A.; Wootan, D.W.

    1997-07-29

    This document provides a printout of the ``Fuel Activity Database`` (version U6) generated by the Hanford DKPRO code and transmitted to the Los Alamos National Laboratory for input to their ``Hanford Defined Waste`` model of waste tank inventories. This fuel activity file consists of 1,276 records--each record representing the activity associated with a batch of spent reactor fuel processed by month (or shorter period) through individual Hanford separations plants between 1944 and 1989. Each record gives the curies for 46 key radionuclides, decayed to a common reference date of January 1, 1994.

  13. An approach to determining the economic feasibility of refuse-derived fuels and materials recovery processing

    SciTech Connect

    Gershman, H.W.

    1980-06-01

    An approach for determining the economic feasibility of refuse-derived fuel production and the recovery of various materials is demonstrated, using data developed for the metropolitan Washington, D.C., area as input. The processing facility, designed to handle 650 tpd of refuse, is described. Since materials revenues can be predicted with a higher degree of certainty than refuse fuel revenues, it is necessary to determine what revenues the sale of solid waste fuel will have to generate for projected economics to be the same as an alternative disposal practice. (1 diagram, 8 references, 6 tables)

  14. /sup 238/Pu fuel processes. Quarterly report, January-March 1981

    SciTech Connect

    Folger, R.L.

    1981-09-01

    Recent process development work indicates that the atmosphere (cover gas) in which /sup 238/PuO/sub 2/ granules are sintered is a critical parameter in the production of General-Purpose Heat Source (GPHS) fuel forms. An acceptable feed material for the direct fabrication of /sup 238/PuO/sub 2/ fuel was produced in the SRP HB-Line using a Pu(III) oxalate direct-strike precipitation technique that was developed at SRL.

  15. The effect of entrainment on starting vortices

    NASA Astrophysics Data System (ADS)

    Rosi, Giuseppe; Rival, David

    2015-11-01

    Recent work shows that vortex detachment behind accelerating plates coincides with when streamlines enclosing the starting vortex (SV) form a full saddle. In the case of a linearly accelerating plate, it can be shown that vorticity-containing mass, and thus the SV's development scale with only dimensionless towed distance, while the SV's circulation scales with the acceleration rate. This results in shear-layer instabilities whose structure is Reynold-number independent, but whose strength scale with Reynolds number. It is hypothesized that the increased strength of the instabilities promotes entrainment, which causes the formation of the full saddle and thereby detachment to occur at an earlier dimensionless towed distance. To test this hypothesis, a circular plate is linearly accelerated from rest to pinch-off with chord-based Reynolds numbers of 103, 104, and 105 at the midpoint of the motion. Planar PIV data is acquired, from which FTLE and enstrophy fields are calculated. Vortex detachment is identified from the dynamics of the FTLE saddles, while the enstrophy fields are used to calculate both the vorticity-containing mass entering from the shear layer and the mass entrained from the quiescent surroundings.

  16. Stochastic entrainment of a stochastic oscillator.

    PubMed

    Wang, Guanyu; Peskin, Charles S

    2015-11-01

    In this work, we consider a stochastic oscillator described by a discrete-state continuous-time Markov chain, in which the states are arranged in a circle, and there is a constant probability per unit time of jumping from one state to the next in a specified direction around the circle. At each of a sequence of equally spaced times, the oscillator has a specified probability of being reset to a particular state. The focus of this work is the entrainment of the oscillator by this periodic but stochastic stimulus. We consider a distinguished limit, in which (i) the number of states of the oscillator approaches infinity, as does the probability per unit time of jumping from one state to the next, so that the natural mean period of the oscillator remains constant, (ii) the resetting probability approaches zero, and (iii) the period of the resetting signal approaches a multiple, by a ratio of small integers, of the natural mean period of the oscillator. In this distinguished limit, we use analytic and numerical methods to study the extent to which entrainment occurs. PMID:26651734

  17. Solar photochemical process engineering for production of fuels and chemicals

    NASA Technical Reports Server (NTRS)

    Biddle, J. R.; Peterson, D. B.; Fujita, T.

    1984-01-01

    The engineering costs and performance of a nominal 25,000 scmd (883,000 scfd) photochemical plant to produce dihydrogen from water were studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6% are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6%. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel.

  18. Solar photochemical process engineering for production of fuels and chemicals

    NASA Technical Reports Server (NTRS)

    Biddle, J. R.; Peterson, D. B.; Fujita, T.

    1985-01-01

    The engineering costs and performance of a nominal 25,000 scmd (883,000 scfd) photochemical plant to produce dihydrogen from water were studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6 percent are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6 percent. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel.

  19. Evaluation of Co-precipitation Processes for the Synthesis of Mixed-Oxide Fuel Feedstock Materials

    SciTech Connect

    Collins, Emory D; Voit, Stewart L; Vedder, Raymond James

    2011-06-01

    The focus of this report is the evaluation of various co-precipitation processes for use in the synthesis of mixed oxide feedstock powders for the Ceramic Fuels Technology Area within the Fuels Cycle R&D (FCR&D) Program's Advanced Fuels Campaign. The evaluation will include a comparison with standard mechanical mixing of dry powders and as well as other co-conversion methods. The end result will be the down selection of a preferred sequence of co-precipitation process for the preparation of nuclear fuel feedstock materials to be used for comparison with other feedstock preparation methods. A review of the literature was done to identify potential nitrate-to-oxide co-conversion processes which have been applied to mixtures of uranium and plutonium to achieve recycle fuel homogeneity. Recent studies have begun to study the options for co-converting all of the plutonium and neptunium recovered from used nuclear fuels, together with appropriate portions of recovered uranium to produce the desired mixed oxide recycle fuel. The addition of recycled uranium will help reduce the safeguard attractiveness level and improve proliferation resistance of the recycled fuel. The inclusion of neptunium is primarily driven by its chemical similarity to plutonium, thus enabling a simple quick path to recycle. For recycle fuel to thermal-spectrum light water reactors (LWRs), the uranium concentration can be {approx}90% (wt.), and for fast spectrum reactors, the uranium concentration can typically exceed 70% (wt.). However, some of the co-conversion/recycle fuel fabrication processes being developed utilize a two-step process to reach the desired uranium concentration. In these processes, a 50-50 'master-mix' MOX powder is produced by the co-conversion process, and the uranium concentration is adjusted to the desired level for MOX fuel recycle by powder blending (milling) the 'master-mix' with depleted uranium oxide. In general, parameters that must be controlled for co

  20. APPLICABILITY OF La-Ce SYSTEMATICS TO PLANETARY SAMPLES.

    USGS Publications Warehouse

    Nakamura, Noboru; Tatsumoto, Mitsunobu; Ludwig, Kenneth R.

    1984-01-01

    Ce isotopic compositions in several terrestrial and extraterrestrial materials were determined in order to investigate the applicability of using Ce as an isotopic tracer to geological processes. Owing to the low abundances of **1**3**8La and **1**3**8Ce in nature, the measurements of **1**3**8Ce/**1**4**0Ce ratios of natural samples have relatively large ( greater than 0. 02%) errors, and the variations in Ce-isotope ratios were barely resolved. A tenuous anticorrelation was observed between epsilon //C//e and epsilon //N//d for terrestrial basalts and granites, indicating that with some improvement in analytical techniques the Ce isotopic composition may prove useful as a tracer for geological processes.

  1. High liquid fuel yielding biofuel processes and a roadmap for the future transportation

    NASA Astrophysics Data System (ADS)

    Singh, Navneet R.

    In a fossil-fuel deprived world when crude oil will be scarce and transportation need cannot be met with electricity and transportation liquid fuel must be produced, biomass derived liquid fuels can be a natural replacement. However, the carbon efficiency of the currently known biomass to liquid fuel conversion processes ranges from 35-40%, yielding 90 ethanol gallon equivalents (ege) per ton of biomass. This coupled with the fact that the efficiency at which solar energy is captured by biomass (<1%) is significantly lower than H 2 (10-27%) and electricity (20-42%), implies that sufficient land area is not available to meet the need for the entire transportation sector. To counter this dilemma, a number of processes have been proposed in this work: a hybrid hydrogen-carbon (H2CAR) process based on biomass gasification followed by the Fischer-Tropsch process such that 100% carbon efficiency is achieved yielding 330 ege/ton biomass using hydrogen derived from a carbon-free energy. The hydrogen requirement for the H2CAR process is 0.33 kg/liter of diesel. To decrease the hydrogen requirement associated with the H2CAR process, a hydrogen bio-oil (H2Bioil) process based on biomass fast-hydropyrolysis/hydrodeoxygenation is proposed which can achieve liquid fuel yield of 215 ege/ton consuming 0.11 kg hydrogen per liter of oil. Due to the lower hydrogen consumption of the H2Bioil process, synergistically integrated transition pathways are feasible where hot syngas derived from coal gasification (H2Bioil-C) or a natural gas reformer (H 2Bioil-NG) is used to supply the hydrogen and process heat for the biomass fast-hydropyrolysis/hydrodeoxygenation. Another off-shoot of the H2Bioil process is the H2Bioil-B process, where hydrogen required for the hydropyrolysis is obtained from gasification of a fraction of the biomass. H2Bioil-B achieves the highest liquid fuel yield (126-146 ege/ton of biomass) reported in the literature for any self-contained conversion of biomass to

  2. Catalysts and process for liquid hydrocarbon fuel production

    DOEpatents

    White, Mark G.; Ranaweera, Samantha A.; Henry, William P.

    2016-08-02

    The present invention provides a novel process and system in which a mixture of carbon monoxide and hydrogen synthesis gas, or syngas, is converted into hydrocarbon mixtures composed of high quality distillates, gasoline components, and lower molecular weight gaseous olefins in one reactor or step. The invention utilizes a novel supported bimetallic ion complex catalyst for conversion, and provides methods of preparing such novel catalysts and use of the novel catalysts in the process and system of the invention.

  3. Process and apparatus for recovery of fissionable materials from spent reactor fuel by anodic dissolution

    DOEpatents

    Tomczuk, Zygmunt; Miller, William E.; Wolson, Raymond D.; Gay, Eddie C.

    1991-01-01

    An electrochemical process and apparatus for the recovery of uranium and plutonium from spent metal clad fuel pins is disclosed. The process uses secondary reactions between U.sup.+4 cations and elemental uranium at the anode to increase reaction rates and improve anodic efficiency compared to prior art processes. In another embodiment of the process, secondary reactions between Cd.sup.+2 cations and elemental uranium to form uranium cations and elemental cadmium also assists in oxidizing the uranium at the anode.

  4. A FEASIBILITY STUDY FOR THE COPROCESSING OF FOSSIL FUELS WITH BIOMASS BY THE HYDROCARB PROCESS

    EPA Science Inventory

    The report describes and gives results of an assessment of a new process concept for the production of carbon and methanol from fossil fuels. The Hydrocarb Process consists of the hydrogasification of carbonaceous material to produce methane, which is subsequently thermally decom...

  5. PROCESS TECHNOLOGY BACKGROUND FOR ENVIRONMENTAL ASSESSMENT/SYSTEMS ANALYSIS UTILIZING RESIDUAL FUEL OIL

    EPA Science Inventory

    The report gives results of environmental and economic assessments of processes using residual oil to generate electricity. Emphasis was on three commercially operating processes: flue gas desulfurization (FGD) of the tail gas from fuel oil burning boilers; removal of the sulfur ...

  6. FEASIBILITY STUDY OF COPROCESSING OF FOSSIL FUELS WITH BIOMASS BY THE HYDROCARB PROCESS

    EPA Science Inventory

    The report describes and gives results of an assessment of a new process concept for the production of carbon and methanol from fossil fuels. he Hydrocarb Process consists of the hydrogasification of carbonaceous material to produce methane, which is subsequently thermally decomp...

  7. Industrial fuel gas plant project. Phase II. Memphis industrial fuel gas plant. Final report. [U-GAS process

    SciTech Connect

    Not Available

    1983-01-01

    The Industrial Fuel Gas Plant produces a nominal 50 billion Btu/day of product gas. The entire IFG production will be sold to MLGW. Under normal conditions, 20% of the output of the plant will be sold by MLGW to the local MAPCO refinery and exchanged for pipeline quality refinery gas. The MAPCO refinery gas will be inserted into the Memphis Natural Gas Distribution System. A portion (normally 10%) of the IFG output of the plant will be diverted to a Credit Generation Unit, owned by MLGW, where the IFG will be upgraded to pipeline quality (950 Btu/SCF). This gas will be inserted into MLGW's Natural Gas Distribution System. The remaining output of the IFG plant (gas with a gross heating value of 300 Btu/SCF) will be sold by MLGW as Industrial Fuel Gas. During periods when the IFG plant is partially or totally off-stream, natural gas from the Memphis Natural Gas Distribution System will be sent to an air mixing unit where the gas will be diluted to a medium Btu content and distributed to the IFG customers. Drawing 2200-1-50-00104 is the plant block flow diagram showing the process sequence and process related support facilities of this industrial plant. Each process unit as well as each process-related support facility is described briefly.

  8. Basal entrainment by Newtonian gravity-driven flows

    NASA Astrophysics Data System (ADS)

    Bates, Belinda; Andreini, Nicolas; Ancey, Christophe

    2016-04-01

    Gravity-driven flows can erode the bed along which they descend and increase their mass by a factor of 10 or more. This process is called basal entrainment. Although documented by field observations and laboratory experiments, it remains poorly understood. We look into this issue by studying eroding dam-break waves. More specifically we would like to determine what happens when a viscous gravity-driven flow generated by releasing a fixed volume of incompressible Newtonian fluid encounters a stationary erodible layer (composed of fluid with the same density and viscosity). Models based on depth-averaged mass and momentum balance equations deal with bed-flow interfaces as shock waves. In contrast, we use an approach involving the long-wave approximation of the Navier-Stokes equations (lubrication theory), and in this context, bed-flow interfaces are acceleration waves that move quickly across thin stationary layers. The incoming flow digs down into the bed, pushing up downstream material, thus advancing the flow front. Extending the method used by Huppert [J. Fluid Mech. 121, 43--58 (1982)] for modelling viscous dam-break waves, we end up with a nonlinear diffusion equation for the flow depth, which is solved numerically. Theory is compared with experimental results. Excellent agreement is found in the limit of low Reynolds numbers (i.e., for flow Reynolds numbers lower than 20) for the front position over time and flow depth profile. The Newtonian model has sometimes been used to describe the flow behaviour of natural materials such as snow and debris suspensions, but the majority of existing approaches rely on more elaborate constitutive equations. So there is no direct application of the results presented here to real flow conditions. Yet, our study sheds light on the mechanisms involved in basal entrainment. We provide evidence that the whole layer of loose material is entrained quickly once the flow makes contact with the erodible layer. As this process occurs

  9. INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS

    SciTech Connect

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

    2004-09-01

    An innovative Diffusion Driven Desalination (DDD) process was recently described where evaporation of mineralized water is driven by diffusion within a packed bed. The energy source to drive the process is derived from low pressure condensing steam within the main condenser of a steam power generating plant. Since waste heat is used to drive the process, the main cost of fresh water production is attributed to the energy cost of pumping air and water through the packed bed. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A combined thermodynamic and dynamic analysis demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3'' Hg. Throughout the past year, the main focus of the desalination process has been on the diffusion tower and direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. An experimental DDD facility has been fabricated, and temperature and humidity data have been collected over a range of flow and thermal conditions. The analyses agree quite well with the current data and the information available in the literature. Direct contact condensers with and without packing have been investigated. It has been experimentally observed that the fresh water production rate is significantly enhanced when packing is added to the direct contact condensers.

  10. On the Development of a Distillation Process for the Electrometallurgical Treatment of Irradiated Spent Nuclear Fuel

    SciTech Connect

    B.R. Westphal; K.C. Marsden; J.C. Price; D.V. Laug

    2008-04-01

    As part of the spent fuel treatment program at the Idaho National Laboratory, a vacuum distillation process is being employed for the recovery of actinide products following an electrorefining process. Separation of the actinide products from a molten salt electrolyte and cadmium is achieved by a batch operation called cathode processing. A cathode processor has been designed and developed to efficiently remove the process chemicals and consolidate the actinide products for further processing. This paper describes the fundamentals of cathode processing, the evolution of the equipment design, the operation and efficiency of the equipment, and recent developments at the cathode processor. In addition, challenges encountered during the processing of irradiated spent nuclear fuel in the cathode processor will be discussed.

  11. Studies on the percolation limit of Ce0.9Gd0.1O1.95 in La0.6Sr0.4Co0.2Fe0.8O3-δ-Ce0.9Gd0.1O1.95 nanocomposites for solid oxide fuel cells application

    NASA Astrophysics Data System (ADS)

    Jamale, Atul P.; Jadhav, S. T.; Dubal, S. U.; Bhosale, C. H.; Jadhav, L. D.

    2015-10-01

    A large difference in thermal expansion coefficient of electrode and electrolyte leads to imperfect electrode/electrolyte interface and hence significant polarization losses in solid oxide fuel cells. To overcome the difficulties associated with electrode and electrode/electrolyte interface, there is need to fabricate the composite cathode. Thus the present paper deals with study of La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)-Ce0.9Gd0.1O1.95(GDC) nanocomposite with different fractions of GDC obtained by physical mixing of combustion synthesized nanopowders. No secondary phases were observed upon sintering at 1100 °C for 2 h affirming the chemical compatibility between LSCF and GDC. The composites with relatively high GDC% have higher density as a consequence of rapid grain growth and less conductivity. The nanocomposite with 50% of GDC showed electric conductivity of 30 Scm-1 at 500 °C and low area specific resistance of 106 Ω cm2 with 10 μs relaxation time at 200 °C.

  12. Catalysts and process for liquid hydrocarbon fuel production

    SciTech Connect

    White, Mark G; Liu, Shetian

    2014-12-09

    The present invention provides a novel process and system in which a mixture of carbon monoxide and hydrogen synthesis gas, or syngas, is converted into hydrocarbon mixtures composed of high quality gasoline components, aromatic compounds, and lower molecular weight gaseous olefins in one reactor or step. The invention utilizes a novel molybdenum-zeolite catalyst in high pressure hydrogen for conversion, as well as a novel rhenium-zeolite catalyst in place of the molybdenum-zeolite catalyst, and provides for use of the novel catalysts in the process and system of the invention.

  13. Turbulent mixing and entrainment in a gravity current

    SciTech Connect

    Ecke, Robert E; Odier, Philippe; Chen, Jun

    2010-01-01

    We present an experimental study of the mixing processes in a gravity current. The turbulent transport of momentum and buoyancy can be described in a very direct and compact form by a Prandtl mixing length model: the turbulent vertical fluxes of momentum and buoyancy are found to scale quadratically with the vertical mean gradients of velocity and density. The scaling coefficient is the square of the mixing lenth, approximately constant over the mixing zone of the stratified shear layer. We show how, in different flow configurations, this length can be related to the shear length of the flow ({var_epsilon}/{partial_derivative}{sub z}u{sup 3}){sup 1/2}. We also study the fluctuations of the momentum and density turbulent fluxes, showing how they relate to the mixing phenomena, and to the entrainment/detrainment balance.

  14. Phase-selective entrainment of nonlinear oscillator ensembles

    NASA Astrophysics Data System (ADS)

    Zlotnik, Anatoly; Nagao, Raphael; Kiss, István Z.; Li-Shin, Jr.

    2016-03-01

    The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological oscillator ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create stable phase patterns in ensembles of heterogeneous nonlinear oscillators without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups into spatiotemporal patterns with multiple phase clusters. The experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information.

  15. Entrainment of Human Alpha Oscillations Selectively Enhances Visual Conjunction Search

    PubMed Central

    Müller, Notger G.; Vellage, Anne-Katrin; Heinze, Hans-Jochen; Zaehle, Tino

    2015-01-01

    The functional role of the alpha-rhythm which dominates the human electroencephalogram (EEG) is unclear. It has been related to visual processing, attentional selection and object coherence, respectively. Here we tested the interaction of alpha oscillations of the human brain with visual search tasks that differed in their attentional demands (pre-attentive vs. attentive) and also in the necessity to establish object coherence (conjunction vs. single feature). Between pre- and post-assessment elderly subjects received 20 min/d of repetitive transcranial alternating current stimulation (tACS) over the occipital cortex adjusted to their individual alpha frequency over five consecutive days. Compared to sham the entrained alpha oscillations led to a selective, set size independent improvement in the conjunction search task performance but not in the easy or in the hard feature search task. These findings suggest that cortical alpha oscillations play a specific role in establishing object coherence through suppression of distracting objects. PMID:26606255

  16. Phase-selective entrainment of nonlinear oscillator ensembles

    DOE PAGESBeta

    Zlotnik, Anatoly V.; Nagao, Raphael; Kiss, Istvan Z.; Li, Jr -Shin

    2016-03-18

    The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological oscillator ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create stable phase patterns in ensembles of heterogeneous nonlinear oscillators without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups intomore » spatiotemporal patterns with multiple phase clusters. As a result, the experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information.« less

  17. Phase-selective entrainment of nonlinear oscillator ensembles

    PubMed Central

    Zlotnik, Anatoly; Nagao, Raphael; Kiss, István Z.; Li, Jr-Shin

    2016-01-01

    The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological oscillator ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create stable phase patterns in ensembles of heterogeneous nonlinear oscillators without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups into spatiotemporal patterns with multiple phase clusters. The experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information. PMID:26988313

  18. Entrainment of Human Alpha Oscillations Selectively Enhances Visual Conjunction Search.

    PubMed

    Müller, Notger G; Vellage, Anne-Katrin; Heinze, Hans-Jochen; Zaehle, Tino

    2015-01-01

    The functional role of the alpha-rhythm which dominates the human electroencephalogram (EEG) is unclear. It has been related to visual processing, attentional selection and object coherence, respectively. Here we tested the interaction of alpha oscillations of the human brain with visual search tasks that differed in their attentional demands (pre-attentive vs. attentive) and also in the necessity to establish object coherence (conjunction vs. single feature). Between pre- and post-assessment elderly subjects received 20 min/d of repetitive transcranial alternating current stimulation (tACS) over the occipital cortex adjusted to their individual alpha frequency over five consecutive days. Compared to sham the entrained alpha oscillations led to a selective, set size independent improvement in the conjunction search task performance but not in the easy or in the hard feature search task. These findings suggest that cortical alpha oscillations play a specific role in establishing object coherence through suppression of distracting objects. PMID:26606255

  19. Phase-selective entrainment of nonlinear oscillator ensembles.

    PubMed

    Zlotnik, Anatoly; Nagao, Raphael; Kiss, István Z; Li, Jr-Shin

    2016-01-01

    The ability to organize and finely manipulate the hierarchy and timing of dynamic processes is important for understanding and influencing brain functions, sleep and metabolic cycles, and many other natural phenomena. However, establishing spatiotemporal structures in biological oscillator ensembles is a challenging task that requires controlling large collections of complex nonlinear dynamical units. In this report, we present a method to design entrainment signals that create stable phase patterns in ensembles of heterogeneous nonlinear oscillators without using state feedback information. We demonstrate the approach using experiments with electrochemical reactions on multielectrode arrays, in which we selectively assign ensemble subgroups into spatiotemporal patterns with multiple phase clusters. The experimentally confirmed mechanism elucidates the connection between the phases and natural frequencies of a collection of dynamical elements, the spatial and temporal information that is encoded within this ensemble, and how external signals can be used to retrieve this information. PMID:26988313

  20. EVALUATION OF A PROCESS TO CONVERT BIOMASS TO METHANOL FUEL

    EPA Science Inventory

    The report gives results of a review of the design of a reactor capable of gasifying approximately 50 lb/hr of biomass for a pilot-scale facility to develop, demonstrate, and evaluate the Hynol Process, a high-temperature, high-pressure method for converting biomass into methanol...

  1. Development of Systems Engineering Model for Spent Fuel Extraction Process

    SciTech Connect

    Sun, Lijian; Royyuru, Haritha; Hsieh, Hsuan-Tsung 'Sean'; Chen, Yitung; Clarksean, Randy; Vandegrift, George; Copple, Jackie; Laidler, James

    2004-07-01

    The mission of the Transmutation Research Program (TRP) at University of Nevada, Las Vegas (UNLV) is to establish a nuclear engineering test bed that can carry out effective transmutation and advanced reactor research and development effort. The Nevada Center for Advanced Computational Methods (NCACM) at UNLV is currently developing the systems engineering model, TRPSEMPro (Transmutation Research Program System Engineering Model Project, that provides process optimization through the automatic adjustment on input parameters, such as feed compositions, stages, flow rates, etc., based on the extraction efficiency of components and concerned output factors. An object-oriented programming (OOP) is considered. Such systems engineering model consists of task manager, task integration and solution monitor modules. A MS SQL server database is implemented for managing data flow from optimization processing. Task manager coordinates and interacts with other two modules. Task integration module works as a flowsheet constructor that builds task hierarchy, input parameter values and constrains. Task solution monitor component presents both in-progress and final outputs in tabulated and graphical formats. The system can monitor parameter justification outputs from optimization toolbox developed by Mathworks' MatLab commercial software. While initial parameter constraint identifications for using optimization process is tedious and time-consuming, the interface also provides a multiple-run process that executes a design matrix without invoking any optimization module. Experimental reports can be flexibly generated through database query and formatting. (authors)

  2. Solid recovered fuel: materials flow analysis and fuel property development during the mechanical processing of biodried waste.

    PubMed

    Velis, Costas A; Wagland, Stuart; Longhurst, Phil; Robson, Bryce; Sinfield, Keith; Wise, Stephen; Pollard, Simon

    2013-03-19

    Material flows and their contributions to fuel properties are balanced for the mechanical section of a mechanical-biological treatment (MBT) plant producing solid recovered fuel (SRF) for the UK market. Insights for this and similar plants were secured through a program of sampling, manual sorting, statistics, analytical property determination, and material flow analysis (MFA) with error propagation and data reconciliation. Approximately three-quarters of the net calorific value (Q(net,p,ar)) present in the combustible fraction of the biodried flow is incorporated into the SRF (73.2 ± 8.6%), with the important contributors being plastic film (30.7 MJ kg(ar)(-1)), other packaging plastic (26.1 MJ kg(ar)(-1)), and paper/card (13.0 MJ kg(ar)(-1)). Nearly 80% w/w of the chlorine load in the biodried flow is incorporated into SRF (78.9 ± 26.2%), determined by the operation of the trommel and air classifier. Through the use of a novel mass balancing procedure, SRF quality is understood, thus improving on the understanding of quality assurance in SRF. Quantification of flows, transfer coefficients, and fuel properties allows recommendations to be made for process optimization and the production of a reliable and therefore marketable SRF product. PMID:23398118

  3. Effect of Process Variables During the Head-End Treatment of Spent Oxide Fuel

    SciTech Connect

    K.J. Bateman; C.D. Morgan; J.F. Berg; D.J. Brough; P.J. Crane; D.G. Cummings; J.J. Giglio; M.W. Huntley; M.J. Rodriquez; J.D. Sommers; R.P. Lind; D.A. Sell

    2006-08-01

    The development of a head-end processing step for spent oxide fuel that applies to both aqueous and pyrometallurgical technologies is being performed by the Idaho National Laboratory, the Oak Ridge National Laboratory, and the Korean Atomic Energy Research Institute through a joint International Nuclear Energy Research Initiative. The processing step employs high temperatures and oxidative gases to promote the oxidation of UO2 to U3O8. Potential benefits of the head-end step include the removal or reduction of fission products as well as separation of the fuel from cladding. The effects of temperature, pressure, oxidative gas, and cladding have been studied with irradiated spent oxide fuel to determine the optimum conditions for process control. Experiments with temperatures ranging from 500oC to 1250oC have been performed on spent fuel using either air or oxygen gas for the oxidative reaction. Various flowrates and applications have been tested with the oxidative gases to discern the effects on the process. Tests have also been performed under vacuum conditions, following the oxidation cycle, at high temperatures to improve the removal of fission products. The effects of cladding on fission product removal have also been investigated with released fuel under vacuum and high temperature conditions. Results from these experiments will be presented as well as operating conditions based on particle size and decladding characteristics.

  4. Techno-economic analysis of biomass to fuel conversion via the MixAlco process.

    PubMed

    Pham, Viet; Holtzapple, Mark; El-Halwagi, Mahmoud

    2010-11-01

    MixAlco is a robust process that converts biomass to fuels and chemicals. A key feature of the MixAlco process is the fermentation, which employs a mixed culture of acid-forming microorganisms to convert biomass components (carbohydrates, proteins, and fats) to carboxylate salts. Subsequently, these intermediate salts are chemically converted to hydrocarbon fuels (gasoline, jet fuel, and diesel). This work focuses on process synthesis, simulation, integration, and cost estimation of the MixAlco process. For the base-case capacity of 40 dry tonne feedstock per hour, the total capital investment is US $5.54/annual gallon of hydrocarbon fuels (US $3.79/annual gallon of ethanol equivalent), and the minimum selling price [with 10% return on investment (ROI), internal hydrogen production, and US $60/tonne biomass] is US $2.56/gal hydrocarbon, which is equivalent to US $1.75/gal ethanol. If plant capacity is increased to 400 tph, the minimum selling price of biomass-derived hydrocarbon fuels is US $1.76/gal hydrocarbon (US $1.20/gal ethanol equivalent), which can compete without subsidies with petroleum-derived hydrocarbons when crude oil sells for about US $65/bbl. At 40 tph, using the average tipping fee for municipal solid waste (US $45/dry tonne) and current price of external hydrogen (US $1/kg), the minimum selling price is only US $1.24/gal hydrocarbon (US $0.85/gal ethanol equivalent). PMID:20596882

  5. Effects of Catalysts on Emissions of Pollutants from Combustion Processes of Liquid Fuels

    NASA Astrophysics Data System (ADS)

    Bok, Agnieszka; Guziałowska-Tic, Joanna; Tic, Wilhelm Jan

    2014-12-01

    The dynamic growth of the use of non-renewable fuels for energy purposes results in demand for catalysts to improve their combustion process. The paper describes catalysts used mainly in the processes of combustion of motor fuels and fuel oils. These catalysts make it possible to raise the efficiency of oxidation processes simultanously reducing the emission of pollutants. The key to success is the selection of catalyst compounds that will reduce harmful emissions of combustion products into the atmosphere. Catalysts are introduced into the combustion zone in form of solutions miscible with fuel or with air supplied to the combustion process. The following compounds soluble in fuel are inclused in the composition of the described catalysts: organometallic complexes, manganese compounds, salts originated from organic acids, ferrocen and its derivatives and sodium chloride and magnesium chloride responsible for burning the soot (chlorides). The priority is to minimize emissions of volatile organic compounds, nitrogen oxides, sulphur oxides, and carbon monoxide, as well as particulate matter.

  6. Out-of-synchrony speech entrainment in developmental dyslexia.

    PubMed

    Molinaro, Nicola; Lizarazu, Mikel; Lallier, Marie; Bourguignon, Mathieu; Carreiras, Manuel

    2016-08-01

    Developmental dyslexia is a reading disorder often characterized by reduced awareness of speech units. Whether the neural source of this phonological disorder in dyslexic readers results from the malfunctioning of the primary auditory system or damaged feedback communication between higher-order phonological regions (i.e., left inferior frontal regions) and the auditory cortex is still under dispute. Here we recorded magnetoencephalographic (MEG) signals from 20 dyslexic readers and 20 age-matched controls while they were listening to ∼10-s-long spoken sentences. Compared to controls, dyslexic readers had (1) an impaired neural entrainment to speech in the delta band (0.5-1 Hz); (2) a reduced delta synchronization in both the right auditory cortex and the left inferior frontal gyrus; and (3) an impaired feedforward functional coupling between neural oscillations in the right auditory cortex and the left inferior frontal regions. This shows that during speech listening, individuals with developmental dyslexia present reduced neural synchrony to low-frequency speech oscillations in primary auditory regions that hinders higher-order speech processing steps. The present findings, thus, strengthen proposals assuming that improper low-frequency acoustic entrainment affects speech sampling. This low speech-brain synchronization has the strong potential to cause severe consequences for both phonological and reading skills. Interestingly, the reduced speech-brain synchronization in dyslexic readers compared to normal readers (and its higher-order consequences across the speech processing network) appears preserved through the development from childhood to adulthood. Thus, the evaluation of speech-brain synchronization could possibly serve as a diagnostic tool for early detection of children at risk of dyslexia. Hum Brain Mapp 37:2767-2783, 2016. © 2016 Wiley Periodicals, Inc. PMID:27061643

  7. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    NASA Technical Reports Server (NTRS)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-01-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide an engineering technology base for development of large scale hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed for conducting experimental investigations. Oxidizer (LOX or GOX) is injected through the head-end over a solid fuel (HTPB) surface. Experiments using fuels supplied by NASA designated industrial companies will also be conducted. The study focuses on the following areas: measurement and observation of solid fuel burning with LOX or GOX, correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study also being conducted at PSU.

  8. Innovative Fresh Water Production Process for Fossil Fuel Plants

    SciTech Connect

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight; Venugopal Jogi

    2005-09-01

    This project concerns a diffusion driven desalination (DDD) process where warm water is evaporated into a low humidity air stream, and the vapor is condensed out to produce distilled water. Although the process has a low fresh water to feed water conversion efficiency, it has been demonstrated that this process can potentially produce low cost distilled water when driven by low grade waste heat. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A dynamic analysis of heat and mass transfer demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3 Hg. The optimum operating condition for the DDD process with a high temperature of 50 C and sink temperature of 25 C has an air mass flux of 1.5 kg/m{sup 2}-s, air to feed water mass flow ratio of 1 in the diffusion tower, and a fresh water to air mass flow ratio of 2 in the condenser. Operating at these conditions yields a fresh water production efficiency (m{sub fW}/m{sub L}) of 0.031 and electric energy consumption rate of 0.0023 kW-hr/kg{sub fW}. Throughout the past year, the main focus of the desalination process has been on the direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. The analyses agree quite well with the current data. Recently, it has been recognized that the fresh water production efficiency can be significantly enhanced with air heating. This type of configuration is well suited for power plants utilizing air-cooled condensers. The experimental DDD facility has been modified with an air heating section, and temperature and humidity data have been collected over a range of flow and thermal conditions. It has been experimentally observed that the fresh water production rate is enhanced when air

  9. Innovative Fresh Water Production Process for Fossil Fuel Plants

    SciTech Connect

    James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

    2006-09-29

    This project concerns a diffusion driven desalination (DDD) process where warm water is evaporated into a low humidity air stream, and the vapor is condensed out to produce distilled water. Although the process has a low fresh water to feed water conversion efficiency, it has been demonstrated that this process can potentially produce low cost distilled water when driven by low grade waste heat. This report summarizes the progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. Detailed heat and mass transfer analyses required to size and analyze the diffusion tower using a heated water input are described. The analyses agree quite well with the current data and the information available in the literature. The direct contact condenser has also been thoroughly analyzed and the system performance at optimal operating conditions has been considered using a heated water/ambient air input to the diffusion tower. The diffusion tower has also been analyzed using a heated air input. The DDD laboratory facility has successfully been modified to include an air heating section. Experiments have been conducted over a range of parameters for two different cases: heated air/heated water and heated air/ambient water. A theoretical heat and mass transfer model has been examined for both of these cases and agreement between the experimental and theoretical data is good. A parametric study reveals that for every liquid mass flux there is an air mass flux value where the diffusion tower energy consumption is minimal and an air mass flux where the fresh water production flux is maximized. A study was also performed to compare the DDD process with different inlet operating conditions as well as different packing. It is shown that the heated air/heated water case is more capable of greater fresh water production with the same energy consumption than the ambient air/heated water process at high liquid mass flux. It is also shown that there can be

  10. Fuel-Flexible Combustion System for Refinery and Chemical Plant Process Heaters

    SciTech Connect

    Benson, Charles; Wilson, Robert

    2014-04-30

    This project culminated in the demonstration of a full-scale industrial burner which allows a broad range of “opportunity” gaseous fuels to be cost-effectively and efficiently utilized while generating minimal emissions of criteria air pollutants. The burner is capable of maintaining a stable flame when the fuel composition changes rapidly. This enhanced stability will contribute significantly to improving the safety and reliability of burner operation in manufacturing sites. Process heating in the refining and chemicals sectors is the primary application for this burner. The refining and chemical sectors account for more than 40% of total industrial natural gas use. Prior to the completion of this project, an enabling technology did not exist that would allow these energy-intensive industries to take full advantage of opportunity fuels and thereby reduce their natural gas consumption. Opportunity gaseous fuels include biogas (from animal and agricultural wastes, wastewater plants, and landfills) as well as syngas (from the gasification of biomass, municipal solid wastes, construction wastes, and refinery residuals). The primary challenge to using gaseous opportunity fuels is that their composition and combustion performance differ significantly from those of conventional fuels such as natural gas and refinery fuel gas. An effective fuel-flexible burner must accept fuels that range widely in quality and change in composition over time, often rapidly. In Phase 1 of this project, the team applied computational fluid dynamics analysis to optimize the prototype burner’s aerodynamic, combustion, heat transfer, and emissions performance. In Phase 2, full-scale testing and refinement of two prototype burners were conducted in test furnaces at Zeeco’s offices in Broken Arrow, OK. These tests demonstrated that the full range of conventional and opportunity fuels could be utilized by the project’s burner while achieving robust flame stability and very low levels of

  11. Demonstrations of safeguards process monitoring sensitivities. Consolidated Fuel Reprocessing Program

    SciTech Connect

    Ehinger, M.H.; Wachter, J.W.

    1986-09-01

    Can process-monitoring information be incorporated into safeguards tests. What level of sensitivity to removals of materials can be achieved with process monitoring tests. These questions are being answered by a series of tests in US facilities. These tests involve full-scale facilities that simulate operating reprocessing plant conditions with natural or depleted uranium solutions as surrogate feed materials. Safeguards systems are in place to detect loss or unauthorized removals of solutions. As part of the tests, actual removals of material from the operating facilities are made. Removals have ranged from several kilograms down to a few hundred grams of uranium. For purposes of the tests, uranium is considered to be plutonium and is the focus of safeguards concerns.

  12. Hot compression process for making edge seals for fuel cells

    DOEpatents

    Dunyak, Thomas J.; Granata, Jr., Samuel J.

    1994-01-01

    A hot compression process for forming integral edge seals in anode and cade assemblies wherein the assemblies are made to a nominal size larger than a finished size, beads of AFLAS are applied to a band adjacent the peripheral margins on both sides of the assemblies, the assemblies are placed in a hot press and compressed for about five minutes with a force sufficient to permeate the peripheral margins with the AFLAS, cooled and cut to finished size.

  13. PLUTONIUM PROCESSING OPTIMIZATION IN SUPPORT OF THE MOX FUEL PROGRAM

    SciTech Connect

    GRAY, DEVIN W.; COSTA, DAVID A.

    2007-02-02

    After Los Alamos National Laboratory (LANL) personnel completed polishing 125 Kg of plutonium as highly purified PuO{sub 2} from surplus nuclear weapons, Duke, COGEMA, Stone, and Webster (DCS) required as the next process stage, the validation and optimization of all phases of the plutonium polishing flow sheet. Personnel will develop the optimized parameters for use in the upcoming 330 kg production mission.

  14. INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS

    SciTech Connect

    James F. Klausner; Renwei Mei; Yi Li; Mohamed Darwish; Diego Acevedo; Jessica Knight

    2003-09-01

    This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system, which is powered by the waste heat from low pressure condensing steam in power plants. The desalination is driven by water vapor saturating dry air flowing through a diffusion tower. Liquid water is condensed out of the air/vapor mixture in a direct contact condenser. A thermodynamic analysis demonstrates that the DDD process can yield a fresh water production efficiency of 4.5% based on a feed water inlet temperature of only 50 C. An example is discussed in which the DDD process utilizes waste heat from a 100 MW steam power plant to produce 1.51 million gallons of fresh water per day. The main focus of the initial development of the desalination process has been on the diffusion tower. A detailed mathematical model for the diffusion tower has been described, and its numerical implementation has been used to characterize its performance and provide guidance for design. The analysis has been used to design a laboratory scale diffusion tower, which has been thoroughly instrumented to allow detailed measurements of heat and mass transfer coefficient, as well as fresh water production efficiency. The experimental facility has been described in detail.

  15. Solvent degradation products in nuclear fuel processing solvents

    SciTech Connect

    Shook, H.E. Jr.

    1988-06-01

    The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

  16. Rhythm as a Coordinating Device: Entrainment with Disordered Speech

    ERIC Educational Resources Information Center

    Borrie, Stephanie A.; Liss, Julie M.

    2014-01-01

    Purpose: The rhythmic entrainment (coordination) of behavior during human interaction is a powerful phenomenon, considered essential for successful communication, supporting social and emotional connection, and facilitating sense-making and information exchange. Disruption in entrainment likely occurs in conversations involving those with speech…

  17. Modeling of neutral entrainment in an FRC thruster

    SciTech Connect

    Brackbill, Jeremiah; Gimelshein, Natalia; Gimelshein, Sergey; Cambier, Jean-Luc; Ketsdever, Andrew

    2012-11-27

    Neutral entrainment in a field reversed configuration thruster is modeled numerically with an implicit PIC code extended to include thermal and chemical interactions between plasma and neutral particles. The contribution of charge exchange and electron impact ionization reactions is analyzed, and the sensitivity of the entrainment efficiency to the plasmoid translation velocity and neutral density is evaluated.

  18. Entrainment and Interfacial Stability in Capillary - Heat Pipes

    NASA Astrophysics Data System (ADS)

    Kim, Bong Hun

    Entrainment phenomena in capillary-driven heat pipes were studied and both analytical and experimental approaches were utilized to identify and better understand the parameters that govern the entrainment of liquid in operating heat pipes. Two experimental investigations, i.e., an aerodynamic simulation and a heat pipe experiment, were conducted using an air-water test channel and a high power heat pipe, respectively. The air-water experiment was used to study the effects of the vapor velocity and wick dimensions on the entrainment phenomenon in heat pipes. The heat pipe experiment was designed to verify the existence of the various modes of entrainment and measure the corresponding entrainment limits. From the comparison of critical velocities obtained in these two experiments, the effectiveness of previous aerodynamic simulations (Ishii and Grolmes, 1975; Matveev et al., 1977) was examined. For both experiments, entrainment was detected by various methods and classified into representative types according to the relative position of the liquid interface to the wick structure and operating conditions. Results of the two experiments were compared with those obtained from previous investigations presented by Cotter (1967), Tien and Chung (1979) and Prenger and Kemme (1981), etc. In addition, the entrainment limit data were theoretically verified using a computer model designed to predict the maximum performance for the given operating conditions. Finally, the entrainment phenomena observed in both the air-water and steam-water experiments were examined from a physical perspective using hydrodynamic instability theories (Kelvin, 1871; Jeffreys, 1926; Miles, 1960).

  19. No Time To Kill: Entrainment and Accelerating Courseware Development.

    ERIC Educational Resources Information Center

    Millington, Paula Crnkovich

    This paper examines the concept of time in multimedia, World Wide Web-based courseware development. The biological concept of entrainment (the alignment of rhythms within and between systems) to accelerate courseware development is explored. The discussion begins with the foundational concepts of entrainment from biological systems and social…

  20. The Impact of Rhythmic Entrainment on a Person with Autism.

    ERIC Educational Resources Information Center

    Orr, Tracy Jo; Myles, Brenda Smith; Carlson, Judith K.

    1998-01-01

    A study investigated the impact of rhythmic entrainment on an 11-year-old girl with autism who engaged in head jerking and screaming. Rhythmic entrainment intervention was more effective when she exhibited behavior that resulted from a moderate level of stress and less effective when stressors were more severe. (CR)

  1. Defining the Entrainment Zone in Stratocumulus-topped Boundary Layers

    NASA Astrophysics Data System (ADS)

    Wang, Q.; Zhou, M.; Kalogiros, J. A.; Lenschow, D. H.; Dai, C.; Wang, S.

    2010-12-01

    The presence of an entrainment zone near the top of the stratocumulus-topped boundary layers has been identified by many early studies. However, the definition of the entrainment zone was rather vague. We have examined the fine vertical variations of cloud liquid water content, wind, temperature and humidity near the stratocumulus top and developed a new method to identify the entrainment zone objectively. Aircraft measurements from various field projects in stratocumulus-topped boundary layers are used, taking advantage of the fast sampling capability of many of the aircraft sensors. Because of the inhomogeneous mixing of two air masses with distinctively different thermodynamic properties, the magnitude of temperature perturbations within the entrainment zone is significantly larger than those above or below. This characteristics is used to define the upper and lower boundaries of the entrainment zone using a wavelet spectra analyses. The definition of the entrainment zone is further evaluated by the presence of a linear mixing line through mixing line analyses. Various other interfaces at the cloud top are also examined, including the cloud interface, temperature interface (inversion), and moisture interface. The heights of these interfaces are examined relative to the height of the entrainment zone. This study also systematically revealed the presence of turbulence above the local cloud top and/or above the entrainment zone. Wind shear near the cloud top is one possible source that generated local turbulence. Other potential sources of turbulence will also be discussed.

  2. CONCEPTUAL PROCESS DESCRIPTION FOR THE MANUFACTURE OF LOW-ENRICHED URANIUM-MOLYBDENUM FUEL

    SciTech Connect

    Daniel M. Wachs; Curtis R. Clark; Randall J. Dunavant

    2008-02-01

    The National Nuclear Security Agency Global Threat Reduction Initiative (GTRI) is tasked with minimizing the use of high-enriched uranium (HEU) worldwide. A key component of that effort is the conversion of research reactors from HEU to low-enriched uranium (LEU) fuels. The GTRI Convert Fuel Development program, previously known as the Reduced Enrichment for Research and Test Reactors program was initiated in 1978 by the United States Department of Energy to develop the nuclear fuels necessary to enable these conversions. The program cooperates with the research reactors’ operators to achieve this goal of HEU to LEU conversion without reduction in reactor performance. The programmatic mandate is to complete the conversion of all civilian domestic research reactors by 2014. These reactors include the five domestic high-performance research reactors (HPRR), namely: the High Flux Isotope Reactor at the Oak Ridge National Laboratory, the Advanced Test Reactor at the Idaho National Laboratory, the National Bureau of Standards Reactor at the National Institute of Standards and Technology, the Missouri University Research Reactor at the University of Missouri–Columbia, and the MIT Reactor-II at the Massachusetts Institute of Technology. Characteristics for each of the HPRRs are given in Appendix A. The GTRI Convert Fuel Development program is currently engaged in the development of a novel nuclear fuel that will enable these conversions. The fuel design is based on a monolithic fuel meat (made from a uranium-molybdenum alloy) clad in Al-6061 that has shown excellent performance in irradiation testing. The unique aspects of the fuel design, however, necessitate the development and implementation of new fabrication techniques and, thus, establishment of the infrastructure to ensure adequate fuel fabrication capability. A conceptual fabrication process description and rough estimates of the total facility throughput are described in this document as a basis for

  3. Head-end process for the reprocessing of HTGR spent fuel

    SciTech Connect

    Chen, J.; Wen, M.

    2013-07-01

    The reprocessing of HTGR spent fuels is in favor of the sustainable development of nuclear energy to realize the maximal use of nuclear resource and the minimum disposal of nuclear waste. The head-end of HTGR spent fuels reprocessing is different from that of the LWR spent fuels reprocessing because of the difference of spent fuel structure. The dismantling of the graphite spent fuel element and the highly effective dissolution of fuel kernel is the most difficult process in the head end of the reprocessing. Recently, some work on the head-end has been done in China. First, the electrochemical method with nitrate salt as electrolyte was studied to disintegrate the graphite matrix from HTGR fuel elements and release the coated fuel particles, to provide an option for the head-end technology of reprocessing. The results show that the graphite matrix can be effectively separated from the coated particle without any damage to the SiC layer. Secondly, the microwave-assisted heating was applied to dissolve the UO{sub 2} kernel from the crashed coated fuel particles. The ceramic UO{sub 2} as the solute has a good ability to absorb the microwave energy. The results of UO{sub 2} kernel dissolution from crushed coated particles by microwave heating show that the total dissolution percentage of UO{sub 2} is more than 99.99% after 3 times cross-flow dissolution with the following parameters: 8 mol/L HNO{sub 3}, temperature 100 Celsius degrees, initial ratio of solid to liquid 1.2 g/ml. (authors)

  4. Applicability of La-Ce systematics to planetary samples

    NASA Technical Reports Server (NTRS)

    Nakamura, N.; Tatsumoto, M.; Ludwig, K. R.

    1984-01-01

    Cesium isotopic compositions in several terrestrial and extraterrestrial materials were determined in order to investigate the applicability of using Ce as an isotropic tracer to geological processes. A tenuous anticorrelation was observed between (epsilon)Ce and (epsilon)Nd for terrestrial basalts and granites, indicating that with some improvement in analytical techniques the Ce isotopic composition may prove useful as tracer for geological processes. A very low (epsilon)Ce predicted from the Ce anomaly in the REE pattern of the Kholar L3 chondrite was not observed, indicating that the anomaly may be caused by terrestrial contamination or alteration.

  5. Simulation of process for electrical energy production based on molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    De Simon, G.; Parodi, F.; Fermeglia, M.; Taccani, R.

    A global molten carbonate fuel cells (MCFC) power plant steady-state simulation is presented. A performance fuel cell numerical model is developed and integrated as a custom block in Aspen plus™for the whole process simulation. The burner/reformer compact unit is built assembling existing Aspen plus™internal blocks. A simulation is obtained with the preliminary input specification to get to the base case and a sensitivity analysis is conducted, in order to find the process parameters whose change improves the global efficiency.

  6. Catalytic hydrosolvation process converts coal to low-sulfur liquid fuel

    NASA Technical Reports Server (NTRS)

    Qader, S. A.

    1978-01-01

    Development of the catalytic hydrosolvation process for converting coal to low-sulfur fuel oil is described in this paper. Coal impregnated with catalyst was slurried with oil, and the mixture was hydrogenated at a temperature of 475 C, and 30 min residence time under 3600 psi pressure. A ton of coal yielded 3.5 bbl of fuel oil containing 0.2% sulfur, with naphtha and C1-C4 hydrocarbon gases as byproducts. A preliminary economic evaluation of the process indicated potential for further development.

  7. Fluvial entrainment of low density peat blocks (block carbon)

    NASA Astrophysics Data System (ADS)

    Warburton, Jeff

    2014-05-01

    In many fluvial environments low density materials are transported in significant quantities and these form an important part of the stream load and /or have a distinct impact on sedimentation in these environments. However, there are significant gaps in understanding of how these materials are entrained and transported by streams and rivers. Eroding upland peatland environments in particular, frequently have fluvial systems in which large eroded peat blocks, often exceeding 1 m in length; form an important component of the stream material flux. Transport of this material is significant in determining rates of erosion but also has important impacts in terms of damage to infrastructure and carbon loss. This paper describes a field experiment designed to establish for the first time the conditions under which large peat blocks (c. > 0.1 m b axis) are initially entrained from a rough gravel bed. The field site is Trout Beck, in the North Pennines, Northern England which is an upland wandering river channel with occasional lateral and mid channel bars. Mean low flow stage is typically 0.2 m but during flood can rapidly rise, in one to two hours, to over 1.5 m. To study peat block entrainment a bespoke data acquisition system consisting of two pressure transducers, four release triggers and time lapse camera was set up. The pressure transducers provided a record of local depth and the release triggers were embedded in peat blocks to record initial motion and arranged on the rough stream bed. The time lapse camera provided verification of timing of block entrainment (during daylight hours) and also provided information on the mechanism of initial movement. Peat blocks were cut from a local source and were equidimensional, ranging in size from 0.1 to 0.7 m. The derived entrainment function is related to a critical depth of entrainment. Results demonstrate that peat blocks are entrained when the local depth approximates the height of the peat block. Blocks frequently shift

  8. Basis for assessing the movement of spent nuclear fuels from wet to dry storage at the Idaho Chemical Processing Plant

    SciTech Connect

    Guenther, R.J.; Gilbert, E.R.; Johnson, A.B.; Lund, A.L.; Pednekar, S.P.; Windes, W.E.

    1994-12-01

    An assessment of the possible material interactions arising from the movement of previously wet stored spent nuclear fuel (SNF) into long-term dry interim storage has been conducted for selected fuels in the Idaho Chemical Processing Plant (ICPP). Three main classes of fuels are addressed: aluminum (Al) clad, stainless steel (SS) clad, and unclad Uranium-Zirconium Hydride (UZrHx) fuel types. Degradation issues for the cladding, fuel matrix material, and storage canister in both wet and dry storage environments are assessed. Possible conditioning techniques to stabilize the fuel and optimum dry environment conditions during storage are also addressed.

  9. Effect of poling process on piezoelectric properties of BCZT - 0.08 wt.% CeO2 lead-free ceramics

    NASA Astrophysics Data System (ADS)

    Chandrakala, E.; Praveen, J. Paul; Das, Dibakar

    2016-05-01

    The properties of lead free piezoelectric materials can be tuned by suitable doping in the A and B sites of the perovskite structure. In the present study, cerium has been identified as a dopant to investigate the piezoelectric properties of lead-free BCZT system. BCZT - 0.08 wt.%CeO2 lead-free ceramics have been synthesized using sol-gel technique and the effects of CeO2 dopant on their phase structure and piezoelectric properties were investigated systematically. Poling conditions, such as temperature, electric field, and poling time have been optimized to get enhanced piezoelectric response. The optimized poling conditions (50°C, 3Ec and 30min) resulted in high piezoelectric charge coefficient d33 ~ 670pC/N, high electromechanical coupling coefficient kp ~ 60% and piezoelectric voltage coefficient g33 ~ 14 mV.m/N for BCZT - 0.08wt.% CeO2 ceramics.

  10. Redox behavior of surface-modified CeO{sub 2}-ZrO{sub 2} catalysts by chemical filing process

    SciTech Connect

    Ozaki, Tetsuya; Masui, Toshiyuki; Machida, Kenichi; Adachi, Ginya; Sakata, Takao; Mori, Hirotaro

    2000-03-01

    Surface modification of CeO{sub 2}-ZrO{sub 2} solid solutions took place using formation and transport of volatile vapor complexes such as AlCl{sub 3}-CeCl{sub 3} and AlCl{sub 3}-ZrCl{sub 4}, which was denoted as chemical filing. XPS analysis showed surface Ce enrichment, and transmission electron microscopy and Raman spectra revealed that a defective phase was formed on the surface of the samples by the chemical filing. The reduction temperature of the samples after the chemical filing was about 50 K lower than that of the fresh sample and further decreased by a reduction/reoxidation cycle. The redox property of the chemically filed sample was maintained even after the redox cycles at high temperatures, indicating its excellent durability compared to the solid solution prepared by a conventional procedure.

  11. 40 CFR 80.513 - What provisions apply to transmix processing facilities and pipelines that produce diesel fuel...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... processing facilities and pipelines that produce diesel fuel from pipeline interface? 80.513 Section 80.513... pipelines that produce diesel fuel from pipeline interface? For purposes of this section, transmix means a mixture of finished fuels, such as pipeline interface, that no longer meets the specifications for a...

  12. 40 CFR 80.513 - What provisions apply to transmix processing facilities and pipelines that produce diesel fuel...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false What provisions apply to transmix processing facilities and pipelines that produce diesel fuel from pipeline interface? 80.513 Section 80.513 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES...

  13. RuO2 nanoparticle-modified (Ce,Mn,Fe)O2/(La,Sr) (Fe,Mn)O3 composite oxide as an active anode for direct hydrocarbon type solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Shin, Tae Ho; Hagiwara, Hidehisa; Ida, Shintaro; Ishihara, Tatsumi

    2015-09-01

    Composite oxide anodes have recently attracted great attention as alternative materials for solid oxide fuel cell anodes because of their potential to overcome the serious performance deterioration associated with the traditional Ni-based cermet. In particular, oxide anodes show a greater tolerance to coke and reoxidation than existing Ni-based cermets. In this study, the anodic performance of a (Ce,Mn,Fe)O2/(La,Sr) (Fe,Mn)O3 composite oxide modified with additional amounts of catalytically active RuO2 nanoparticles was investigated. Heat treatment resulted in highly dispersed RuO2 particles (ca. 10 nm). Anodes containing 10 wt% added RuO2 exhibited fairly high maximum power densities of 0.3 and 1.5 W cm-2 in H2 and C3H8, respectively, at 800 °C. The cells showed stable power density and negligible carbon formation even after 50 h of operation at 1 A cm-2. The increased power density was assigned to decreased anodic overpotential and internal resistance losses because RuO2 nanoparticles contribute to the increase in electrical conductivity.

  14. Stability of La0.6Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 cathodes during sintering and solid oxide fuel cell operation

    NASA Astrophysics Data System (ADS)

    Kiebach, Ragnar; Zhang, Wei-Wei; Zhang, Wei; Chen, Ming; Norrman, Kion; Wang, Hsiang-Jen; Bowen, Jacob R.; Barfod, Rasmus; Hendriksen, Peter Vang

    2015-06-01

    Degradation phenomena of La0.58Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 (LSCF/CGO) cathodes were investigated via post-mortem analyses of an experimental solid oxide fuel cell (SOFC) stack tested at 700 °C for 2000 h using advanced electron microscopy (SEM-EDS, HR-TEM-EDS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Similar studies were carried out on non-tested reference cells for comparison. The analysis focused on the LSCF/CGO cathode and the CGO barrier layer, as the cathode degradation can be a major contributor to the overall degradation in this type of SOFC. SEM-EDS and TOF-SIMS were used to investigate inter-diffusion across the barrier layer-electrolyte interface and the barrier layer-cathode interface. In addition, TOF-SIMS data were employed to investigate impurity distribution before and after testing. HR-TEM-EDS was used to investigate possible phase segregation in the LSCF and to look for reaction between the phases. The results show that phase separation and inter-diffusion across the cathode-barrier layer interface and the barrier layer-electrolyte interface happened mainly during sintering and cathode firing, and to a very little degree during the test period.

  15. Title: Performances of YBaCo1.4Cu0.6O5+ -Ce0.8Sm0.2O1.9 composite cathodes for intermediatetemperature solid oxide fuel cells

    DOE PAGESBeta

    Wang, Lizhong; Peng, Lu; Hu, Michael Z.; Lyu, Shiquan; Meng, Xiangwei; Yu, Bo; Wei, Maobin; Fan, Hougang; Yang, Lili

    2015-01-01

    The electrochemical properties of YBaCo1.4Cu0.6O5+ xCe0.8Sm0.2O1.9 (YBCC xSDC, x = 20, 30, 40, 50, wt%) have been investigated for the potential application in intermediate-temperature solid oxide fuel cells (IT-SOFCs). No chemical reactions between YBCC cathode and SDC electrolyte, and YBCC and La0.9Sr0.1Ga0.8Mg0.2O3- (LSGM) occur. The thermal expansion coefficient (TEC) of YBCC cathode decreases with SDC addition. The TEC of YBCC 30SDC cathode is 13.60 10-6 K-1 from 30 to 850 oC in air and it exhibits the best electrochemical performance among the YBCC xSDC cathodes. The polarization resistance (Rp) of YBCC 30SDC is 0.027 cm2 at 850 oC, 0.044 cm2more » at 800 oC and 0.075 cm2 at 750 oC. The maximum power density value of electrolyte-based cell with YBCC 30SDC cathode is 662, 483 and 319 mW cm 2 at 850, 800 and 750 oC, respectively. Preliminary results indicate that YBCC 30SDC is especially promising as a cathode for IT-SOFCs.« less

  16. Performances of YBaCo1.4Cu0.6O5+δ–Ce0.8Sm0.2O1.9 composite cathodes for intermediate-temperature solid oxide fuel cells

    DOE PAGESBeta

    Wang, Lizhong; Peng, Lu; Hu, Michael Z.; Lü, Shiquan; Meng, Xiangwei; Yu, Bo; Wei, Maobin; Fan, Hougang; Yang, Lili

    2015-08-20

    In this paper, the electrochemical properties of YBaCo1.4Cu0.6O5+δ–xCe0.8Sm0.2O1.9 (YBCC–xSDC, x=20, 30, 40, 50 wt%) have been investigated for the potential application in intermediate-temperature solid oxide fuel cells (IT-SOFCs). No chemical reactions between YBCC cathode and SDC electrolyte, and YBCC and La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) occur. The thermal expansion coefficient (TEC) of YBCC cathode decreases with SDC addition. The TEC of YBCC–30SDC cathode is 13.60×10–6 K-1 from 30 to 850 °C in air and it exhibits the best electrochemical performance among the YBCC–xSDC cathodes. The polarization resistance (Rp) of YBCC–30SDC is 0.027 Ω cm2 at 850 °C, 0.044 Ω cm2 at 800 °Cmore » and 0.075 Ω cm2 at 750 °C. The maximum power density value of electrolyte-based cell with YBCC–30SDC cathode is 662, 483 and 319 mW cm-2 at 850, 800 and 750 °C, respectively. Finally, preliminary results indicate that YBCC–30SDC is especially promising as a cathode for IT-SOFCs.« less

  17. Ground-Based Remote Retrievals of Cumulus Entrainment Rates

    SciTech Connect

    Wagner, Timothy J.; Turner, David D.; Berg, Larry K.; Krueger, Steven K.

    2013-07-26

    While fractional entrainment rates for cumulus clouds have typically been derived from airborne observations, this limits the size and scope of available data sets. To increase the number of continental cumulus entrainment rate observations available for study, an algorithm for retrieving them from ground-based remote sensing observations has been developed. This algorithm, called the Entrainment Rate In Cumulus Algorithm (ERICA), uses the suite of instruments at the Southern Great Plains (SGP) site of the United States Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility as inputs into a Gauss-Newton optimal estimation scheme, in which an assumed guess of the entrainment rate is iteratively adjusted through intercomparison of modeled liquid water path and cloud droplet effective radius to their observed counterparts. The forward model in this algorithm is the Explicit Mixing Parcel Model (EMPM), a cloud parcel model that treats entrainment as a series of discrete entrainment events. A quantified value for measurement uncertainty is also returned as part of the retrieval. Sensitivity testing and information content analysis demonstrate the robust nature of this method for retrieving accurate observations of the entrainment rate without the drawbacks of airborne sampling. Results from a test of ERICA on three months of shallow cumulus cloud events show significant variability of the entrainment rate of clouds in a single day and from one day to the next. The mean value of 1.06 km-¹ for the entrainment rate in this dataset corresponds well with prior observations and simulations of the entrainment rate in cumulus clouds.

  18. High-Resolution Entrainment in Stratocumulus During the POST Campaign

    NASA Astrophysics Data System (ADS)

    Gerber, H. E.

    2012-12-01

    In July and August of 2008 an NSF-supported field campaign called POST (Physics of Stratocumulus Top) was conducted off the California coast using the fully-instrumented Twin Otter aircraft from the Naval Post Graduate School. POST provided the first opportunity to closely co-locate on an aircraft high-rate and time synchronized microphysics (PVM; LWC and effective radius) and thermodynamics (UFT; Ultra-Fast Temperature) probes and a gust probe to produce measurements of entrainment fluxes and features over entrainment scales thought to be important in warm stratocumulus (Sc). This combination of probes permitted investigating the properties of individual entrained parcels Seventeen flights were conducted during POST in a quasi-Lagrangian fashion in largely unbroken stratocumulus. The horizontal fight path was adjusted to follow the mean air velocity in the Sc. The vertical flight path concentrated on flying between 100-m above and below the cloud-top interface; and some additional profiles were flown to various higher and lower levels where flux runs were made. This presentation describes the analysis of this unique and excellent data set including the following: The data permitted testing Lilly's classical theory for the entrainment velocity where its application requires strong jumps of temperature and moisture across the inversion located above cloud top, a linear flux of the entrained scalar below cloud top, and entrained parcels that descend. All flights showed Sc with wind shear and mixing at cloud top with some strong enough to dissipate the Sc. The relationship between shear and entrainment velocity is described. The pdf of the horizontal size of entrainment parcels vs entrainment flux is established for all flights to help in choosing grid-sizes for modeling. High -resolution in-cloud temperature and LWC measurements in entrained parcels reveal the relative importance of radiative cooling vs cooling by liquid water evaporation in causing buoyancy reversal

  19. Low Emissions Burner Technology for Metal Processing Industry using Byproducts and Biomass Derived Liquid Fuels

    SciTech Connect

    Agrawal, Ajay; Taylor, Robert

    2013-09-30

    path forward to utilize both fossil and alternative liquid fuels in the same combustion system. In particular, experiments show that straight VO can be cleanly combusted without the need for chemical processing or preheating steps, which can result in significant economic and environmental benefits. Next, low-emission combustion of glycerol/methane was achieved by utilizing FB injector to yield fine droplets of highly viscous glycerol. Heat released from methane combustion further improves glycerol pre-vaporization and thus its clean combustion. Methane addition results in an intensified reaction zone with locally high temperatures near the injector exit. Reduction in methane flow rate elongates the reaction zone, which leads to higher CO emissions and lower NOx emissions. Similarly, higher air to liquid (ALR) mass ratio improves atomization and fuel pre-vaporization and shifts the flame closer to the injector exit. In spite of these internal variations, all fuel mixes of glycerol with methane produced similar CO and NOx emissions at the combustor exit. Results show that FB concept provides low emissions with the flexibility to utilize gaseous and highly viscous liquid fuels, straight VO and glycerol, without preheating or preprocessing the fuels. Following these initial experiments in quartz combustor, we demonstrated that glycerol combustion can be stably sustained in a metal combustor. Phase Doppler Particle Analyzer (PDPA) measurements in glycerol/methane flames resulted in flow-weighted Sauter Mean Diameter (SMD) of 35 to 40 μm, depending upon the methane percentage. This study verified that lab-scale dual-fuel burner using FB injector can successfully atomize and combust glycerol and presumably other highly viscous liquid fuels at relatively low HRR (<10 kW). For industrial applications, a scaled-up glycerol burner design thus seemed feasible.

  20. Modeling of combustion processes in a solid fuel particle

    SciTech Connect

    Howard, D.W.

    1989-01-01

    During the production of granules or uranium oxide, granules of ion-exchange resin, loaded with uranium ions, are burned to remove the resin matrix and leave a uranium oxide ''ash''. Under some conditions of combustion, the oxide granules are produced in a highly fractured, porous state, while other conditions result in hard, dense, solid granules. ABAQUS was used to model the physical processes occurring during combustion: heat transfer with a very non-linear temperature dependent rate of heat generation, diffusion of reactants and products, and stress/strain resulting from the differential temperatures and from the phase changes during the combustion. The ABAQUS simulation was very successful in explaining the differences in morphology of the granules under different conditions, and in leading to control strategies to produce the desired morphology. However, some of the limitations of ABAQUS prevented obtaining as accurate a simulation as desired. 10 figs.

  1. PROCESSING OF URANIUM-METAL-CONTAINING FUEL ELEMENTS

    DOEpatents

    Moore, R.H.

    1962-10-01

    A process is given for recovering uranium from neutronbombarded uranium- aluminum alloys. The alloy is dissolved in an aluminum halide--alkali metal halide mixture in which the halide is a mixture of chloride and bromide, the aluminum halide is present in about stoichiometric quantity as to uranium and fission products and the alkali metal halide in a predominant quantity; the uranium- and electropositive fission-products-containing salt phase is separated from the electronegative-containing metal phase; more aluminum halide is added to the salt phase to obtain equimolarity as to the alkali metal halide; adding an excess of aluminum metal whereby uranium metal is formed and alloyed with the excess aluminum; and separating the uranium-aluminum alloy from the fission- productscontaining salt phase. (AEC)

  2. Modeling of combustion processes in a solid fuel particle

    SciTech Connect

    Howard, D.W.

    1990-01-01

    During the production of granules of uranium oxide, granules of ion exchange resin, loaded with uranium ions, are burned to remove the resin matrix and leave a uranium oxide ash''. Under some conditions of combustion, the oxide granules are produced in a highly fractured, porous state, while other conditions result in hard, dense, solid granules. ABAQUS, a commercial finite-element code, run on an IBM 3090, was used to model the physical processes occurring during combustion: heat transfer with a very nonlinear temperature-dependent rate of heat generation, diffusion of reactants and products, and stress/strain resulting from the differential temperatures and from the phase changes during the combustion. The ABAQUS simulation successfully explained the differences in morphology of the granules under different conditions, and lead to control strategies to produce the desired morphology. 10 figs.

  3. Exploring how musical rhythm entrains brain activity with electroencephalogram frequency-tagging.

    PubMed

    Nozaradan, Sylvie

    2014-12-19

    The ability to perceive a regular beat in music and synchronize to this beat is a widespread human skill. Fundamental to musical behaviour, beat and meter refer to the perception of periodicities while listening to musical rhythms and often involve spontaneous entrainment to move on these periodicities. Here, we present a novel experimental approach inspired by the frequency-tagging approach to understand the perception and production of rhythmic inputs. This approach is illustrated here by recording the human electroencephalogram responses at beat and meter frequencies elicited in various contexts: mental imagery of meter, spontaneous induction of a beat from rhythmic patterns, multisensory integration and sensorimotor synchronization. Collectively, our observations support the view that entrainment and resonance phenomena subtend the processing of musical rhythms in the human brain. More generally, they highlight the potential of this approach to help us understand the link between the phenomenology of musical beat and meter and the bias towards periodicities arising under certain circumstances in the nervous system. Entrainment to music provides a highly valuable framework to explore general entrainment mechanisms as embodied in the human brain. PMID:25385771

  4. Entrainment of bed sediment by debris flows: results from large-scale experiments

    USGS Publications Warehouse

    Reid, Mark E.; Iverson, Richard M.; Logan, Matthew; LaHusen, Richard G.; Godt, Jonathan W.; Griswold, Julie P.

    2011-01-01

    When debris flows grow by entraining sediment, they can become especially hazardous owing to increased volume, speed, and runout. To investigate the entrainment process, we conducted eight largescale experiments in the USGS debris-flow flume. In each experiment, we released a 6 m3 water-saturated debris flow across a 47-m long, ~12-cm thick bed of partially saturated sediment lining the 31º flume. Prior to release, we used low-intensity overhead sprinkling and real-time monitoring to control the bed-sediment wetness. As each debris flow descended the flume, we measured the evolution of flow thickness, basal total normal stress, basal pore-fluid pressure, and sediment scour depth. When debris flows traveled over relatively dry sediment, net scour was minimal, but when debris flows traveled over wetter sediment (volumetric water content > 0.22), debris-flow volume grew rapidly and flow speed and runout were enhanced. Data from scour sensors showed that entrainment occurred by rapid (5-10 cm/s), progressive scour rather than by mass failure at depth. Overriding debris flows rapidly generated high basal pore-fluid pressures when they loaded and deformed bed sediment, and in wetter beds these pressures approached lithostatic levels. Reduction of intergranular friction within the bed sediment thereby enhanced scour efficiency, entrainment, and runout.

  5. A Simple State-Determined Model Reproduces Entrainment and Phase-Locking of Human Walking

    PubMed Central

    Ahn, Jooeun; Hogan, Neville

    2012-01-01

    Theoretical studies and robotic experiments have shown that asymptotically stable periodic walking may emerge from nonlinear limit-cycle oscillators in the neuro-mechanical periphery. We recently reported entrainment of human gait to periodic mechanical perturbations with two essential features: 1) entrainment occurred only when the perturbation period was close to the original (preferred) walking period, and 2) entrainment was always accompanied by phase locking so that the perturbation occurred at the end of the double-stance phase. In this study, we show that a highly-simplified state-determined walking model can reproduce several salient nonlinear limit-cycle behaviors of human walking: 1) periodic gait that is 2) asymptotically stable; 3) entrainment to periodic mechanical perturbations only when the perturbation period is close to the model's unperturbed period; and 4) phase-locking to locate the perturbation at the end of double stance. Importantly, this model requires neither supra-spinal control nor an intrinsic self-sustaining neural oscillator such as a rhythmic central pattern generator. Our results suggest that several prominent limit-cycle features of human walking may stem from simple afferent feedback processes without significant involvement of supra-spinal control or a self-sustaining oscillatory neural network. PMID:23152761

  6. Exploring how musical rhythm entrains brain activity with electroencephalogram frequency-tagging

    PubMed Central

    Nozaradan, Sylvie

    2014-01-01

    The ability to perceive a regular beat in music and synchronize to this beat is a widespread human skill. Fundamental to musical behaviour, beat and meter refer to the perception of periodicities while listening to musical rhythms and often involve spontaneous entrainment to move on these periodicities. Here, we present a novel experimental approach inspired by the frequency-tagging approach to understand the perception and production of rhythmic inputs. This approach is illustrated here by recording the human electroencephalogram responses at beat and meter frequencies elicited in various contexts: mental imagery of meter, spontaneous induction of a beat from rhythmic patterns, multisensory integration and sensorimotor synchronization. Collectively, our observations support the view that entrainment and resonance phenomena subtend the processing of musical rhythms in the human brain. More generally, they highlight the potential of this approach to help us understand the link between the phenomenology of musical beat and meter and the bias towards periodicities arising under certain circumstances in the nervous system. Entrainment to music provides a highly valuable framework to explore general entrainment mechanisms as embodied in the human brain. PMID:25385771

  7. Characterization of Used Nuclear Fuel with Multivariate Analysis for Process Monitoring

    SciTech Connect

    Dayman, Kenneth J.; Coble, Jamie B.; Orton, Christopher R.; Schwantes, Jon M.

    2014-01-01

    The Multi-Isotope Process (MIP) Monitor combines gamma spectroscopy and multivariate analysis to detect anomalies in various process streams in a nuclear fuel reprocessing system. Measured spectra are compared to models of nominal behavior at each measurement location to detect unexpected changes in system behavior. In order to improve the accuracy and specificity of process monitoring, fuel characterization may be used to more accurately train subsequent models in a full analysis scheme. This paper presents initial development of a reactor-type classifier that is used to select a reactor-specific partial least squares model to predict fuel burnup. Nuclide activities for prototypic used fuel samples were generated in ORIGEN-ARP and used to investigate techniques to characterize used nuclear fuel in terms of reactor type (pressurized or boiling water reactor) and burnup. A variety of reactor type classification algorithms, including k-nearest neighbors, linear and quadratic discriminant analyses, and support vector machines, were evaluated to differentiate used fuel from pressurized and boiling water reactors. Then, reactor type-specific partial least squares models were developed to predict the burnup of the fuel. Using these reactor type-specific models instead of a model trained for all light water reactors improved the accuracy of burnup predictions. The developed classification and prediction models were combined and applied to a large dataset that included eight fuel assembly designs, two of which were not used in training the models, and spanned the range of the initial 235U enrichment, cooling time, and burnup values expected of future commercial used fuel for reprocessing. Error rates were consistent across the range of considered enrichment, cooling time, and burnup values. Average absolute relative errors in burnup predictions for validation data both within and outside the training space were 0.0574% and 0.0597%, respectively. The errors seen in this

  8. Nuclear Solid Waste Processing Design at the Idaho Spent Fuels Facility

    SciTech Connect

    Dippre, M. A.

    2003-02-25

    A spent nuclear fuels (SNF) repackaging and storage facility was designed for the Idaho National Engineering and Environmental Laboratory (INEEL), with nuclear solid waste processing capability. Nuclear solid waste included contaminated or potentially contaminated spent fuel containers, associated hardware, machinery parts, light bulbs, tools, PPE, rags, swabs, tarps, weld rod, and HEPA filters. Design of the nuclear solid waste processing facilities included consideration of contractual, regulatory, ALARA (as low as reasonably achievable) exposure, economic, logistical, and space availability requirements. The design also included non-attended transfer methods between the fuel packaging area (FPA) (hot cell) and the waste processing area. A monitoring system was designed for use within the FPA of the facility, to pre-screen the most potentially contaminated fuel canister waste materials, according to contact- or non-contact-handled capability. Fuel canister waste materials which are not able to be contact-handled after attempted decontamination will be processed remotely and packaged within the FPA. Noncontact- handled materials processing includes size-reduction, as required to fit into INEEL permitted containers which will provide sufficient additional shielding to allow contact handling within the waste areas of the facility. The current design, which satisfied all of the requirements, employs mostly simple equipment and requires minimal use of customized components. The waste processing operation also minimizes operator exposure and operator attendance for equipment maintenance. Recently, discussions with the INEEL indicate that large canister waste materials can possibly be shipped to the burial facility without size-reduction. New waste containers would have to be designed to meet the drop tests required for transportation packages. The SNF waste processing facilities could then be highly simplified, resulting in capital equipment cost savings, operational

  9. Ozone entrainment flux using ozone DIAL and Compact Wind Aerosol Lidar (CWAL) in Huntsville AL

    NASA Astrophysics Data System (ADS)

    Huang, G.; Newchurch, M.; kuang, S.; Wang, L.; Cantrell, W.

    2013-12-01

    Previous studies have proved that the impact of high ozone amounts in the residual layer can account for up to 80% of the surface ozone maxima during the following day. This high ozone in the residual layer mixes into to the Planetary Boundary Layer (PBL) through the entrainment processes as the growth of PBL occurs in the morning. Conversely, anthropogenic pollutants emitted from the surface mix into the Free Troposphere (FT) and are transported to other places. Therefore, entrainment flux is one of the important connections between the local-scale/urban-scale and the regional scale. In this study, we will present a study of ozone entrainment fluxes using continuous observation by co-located ozone DIAL and Compact Wind Aerosol Lidar (CWAL) at the campus of University of Alabama in Huntsville (UAH). As a part of Tropospheric Ozone Lidar NETwork (TOLNET), UAH ozone DIAL can provide continuous ozone observation at the range of 125 m AGL to 12 km, with 10-min temporal resolution and 150 - 550 m vertical resolution [Kuang et al., 2013]. We also perform an ozone budget study using Dutch Atmospheric Large-Eddy Simulation (DALES), reasonable approximations of dry deposition, in conjunction with ozone entrainment flux observations. We work towards building a comprehensive understanding of the quantitative impacts of ozone entrainment processes on surface ozone amounts in a medium-sized urban area like Huntsville AL. Shi Kuang, Michael J. Newchurch, John Burris, and Xiong Liu, "Ground-based lidar for atmospheric boundary layer ozone measurements," Appl. Opt. 52, 3557-3566 (2013)

  10. Heterogeneous catalytic process for alcohol fuels from syngas. Fourth quarterly technical progress report, October--December 1992

    SciTech Connect

    Not Available

    1992-12-31

    The principal objectives of this project are to discover and evaluate novel heterogeneous catalysts for conversion of syngas to oxygenates having use as fuel enhancers, to explore novel reactor and process concepts applicable in this process, and to develop the best total process for conversion of syngas to liquid fuels.

  11. Advanced spent fuel conditioning process (ACP) progress with respect to remote operation and maintenance

    SciTech Connect

    Lee, Hyo Jik; Lee, Jong Kwang; Park, Byung Suk; Yoon, Ji Sup

    2007-07-01

    Korea Atomic Energy Research Institute (KAERI) has been developing an Advanced Spent Fuel Conditioning Process (ACP) to reduce the volume of spent fuel, and the construction of the ACP facility (ACPF) for a demonstration of its technical feasibility has been completed. In 2006 two inactive demonstrations were performed with simulated fuels in the ACPF. Accompanied by process equipment performance tests, its remote operability and maintainability were also tested during that time. Procedures for remote operation tasks are well addressed in this study and evaluated thoroughly. Also, remote maintenance and repair tasks are addressed regarding some important modules with a high priority order. The above remote handling test's results provided a lot of information such as items to be revised to improve the efficiency of the remote handling tasks. This paper deals with the current status of ACP and the progress of remote handling of ACPF. (authors)

  12. Sinterability and ionic conductivity of coprecipitated Ce 0.8Gd 0.2O 2- δ powders treated via a high-energy ball-milling process

    NASA Astrophysics Data System (ADS)

    Zhang, T. S.; Ma, J.; Kong, L. B.; Hing, P.; Leng, Y. J.; Chan, S. H.; Kilner, J. A.

    Ceria-based solid solutions are promising electrolytes for intermediate-temperature, solid oxide fuel cells. The effect of a dry, high-energy, ball-milling process on the sintering and densification behaviour of coprecipitated ceria-based powders is investigated by means of X-ray diffraction, Brunauer-Emmett-Teller (BET) surface-area measurements, density measurements, and electron microscopy. The dry ball-milling process leads to (i) a larger specific surface-area with weak agglomeration; (ii) rearrangement of grains into dense granules; (iii) a higher green density. These effects significantly reduce sintering temperatures and promote densification of ceria-based ceramics. Moreover, a comparison is made of the sintering behaviour and ionic conductivity of the milled samples with and without cobalt oxide doping. Cobalt oxide is a very effective sintering aid, but usually results in an enlarged grain-boundary effect for Si-containing samples. Thus, since SiO 2 is a ubiquitous background impurity in both raw materials and ceramic processing, the dry ball-milling process is a more feasible method for improving the sinterability of coprecipitated ceria-based powders.

  13. Alternative fuel vehicles for the state fleets: Results of the 5-year planning process

    SciTech Connect

    Not Available

    1993-05-01

    This report documents the first attempt by the Department of Energy (DOE) to work with states to prepare five-year Alternative Fuel Vehicle (AFV) acquisition plans to identify alternative fuels and vehicles that they are planning on or would like to acquire. The DOE Regional Support Offices (RSOs) met with representatives from the states in their regions and assisted in the preparation of the plans. These plans will be used in conjunction with previously gathered Federal five-year plans to encourage Original Equipment Manufacturers (OEMs) to expand the variety of AFVs produced, reduce the incremental cost of AFVs, and to encourage fuel suppliers to expand the alternative fuel infrastructure and alternative fuel availability. By identifying the needs and requirements of state fleets, DOE can begin to describe the specific nature of the future state fleets, and establish a defined market for OEMs and fuel suppliers. DOE initiated the development and collection of the state five-year plans before the signing of the Energy Policy Act, to raise the awareness of states that they will be required by law to acquire AFVs. As a result, several states that had no AFV acquisition plan when queried have developed or are in the process of developing plans. The DOE and its RSOs are still working with the states to develop and refine acquisition plans, and this report should be treated as documentation of work in progress.

  14. Fuel processing in integrated micro-structured heat-exchanger reactors

    NASA Astrophysics Data System (ADS)

    Kolb, G.; Schürer, J.; Tiemann, D.; Wichert, M.; Zapf, R.; Hessel, V.; Löwe, H.

    Micro-structured fuel processors are under development at IMM for different fuels such as methanol, ethanol, propane/butane (LPG), gasoline and diesel. The target application are mobile, portable and small scale stationary auxiliary power units (APU) based upon fuel cell technology. The key feature of the systems is an integrated plate heat-exchanger technology which allows for the thermal integration of several functions in a single device. Steam reforming may be coupled with catalytic combustion in separate flow paths of a heat-exchanger. Reactors and complete fuel processors are tested up to the size range of 5 kW power output of a corresponding fuel cell. On top of reactor and system prototyping and testing, catalyst coatings are under development at IMM for numerous reactions such as steam reforming of LPG, ethanol and methanol, catalytic combustion of LPG and methanol, and for CO clean-up reactions, namely water-gas shift, methanation and the preferential oxidation of carbon monoxide. These catalysts are investigated in specially developed testing reactors. In selected cases 1000 h stability testing is performed on catalyst coatings at weight hourly space velocities, which are sufficiently high to meet the demands of future fuel processing reactors.

  15. Heterogeneous nucleation of entrained eutectic Si in high purity melt spun Al-Si alloys investigated by entrained droplet technique and DSC

    NASA Astrophysics Data System (ADS)

    Li, J. H.; Albu, M.; Ludwig, T. H.; Hofer, F.; Arnberg, L.; Schumacher, P.

    2016-03-01

    Entrained droplet technique and DSC analyses were employed to investigate the influence of trace elements of Sr, Eu and P on the heterogeneous nucleation of entrained eutectic Si in high purity melt spun Al-5wt.% Si alloys. Sr and Eu addition was found to exert negative effects on the nucleation process, while an increased undercooling was observed. This can be attributed to the formation of phosphide compounds having a lower free energy and hence may preferentially form compared to AlP. Only a trace P addition was found to have a profound effect on the nucleation process. The nucleation kinetics is discussed on the basis of the classical nucleation theory and the free growth model, respectively. The estimated AlP patch size was found to be sufficient for the free growth of Si to occur within the droplets, which strongly indicates that the nucleation of Si on an AlP patch or AlP particle is a limiting step for free growth. The maximum nucleation site density within one droplet is directly related to the size distribution of AlP particles or AlP patches for Si nucleation, but is independent of the cooling rates. Although the nucleation conditions were optimized in entrained droplet experiments, the observed mechanisms are also valid at moderate cooling conditions, such as in shape casting.

  16. Process for the production of fuel gas from coal

    DOEpatents

    Patel, Jitendra G.; Sandstrom, William A.; Tarman, Paul B.

    1982-01-01

    An improved apparatus and process for the conversion of hydrocarbonaceous materials, such as coal, to more valuable gaseous products in a fluidized bed gasification reaction and efficient withdrawal of agglomerated ash from the fluidized bed is disclosed. The improvements are obtained by introducing an oxygen containing gas into the bottom of the fluidized bed through a separate conduit positioned within the center of a nozzle adapted to agglomerate and withdraw the ash from the bottom of the fluidized bed. The conduit extends above the constricted center portion of the nozzle and preferably terminates within and does not extend from the nozzle. In addition to improving ash agglomeration and withdrawal, the present invention prevents sintering and clinkering of the ash in the fluidized bed and permits the efficient recycle of fine material recovered from the product gases by contacting the fines in the fluidized bed with the oxygen as it emanates from the conduit positioned within the withdrawal nozzle. Finally, the present method of oxygen introduction permits the efficient recycle of a portion of the product gases to the reaction zone to increase the reducing properties of the hot product gas.

  17. Percentage entrainment of constituent loads in urban runoff, south Florida

    USGS Publications Warehouse

    Miller, R.A.

    1985-01-01

    Runoff quantity and quality data from four urban basins in south Florida were analyzed to determine the entrainment of total nitrogen, total phosphorus, total carbon, chemical oxygen demand, suspended solids, and total lead within the stormwater runoff. Land use of the homogeneously developed basins are residential (single family), highway, commercial, and apartment (multifamily). A computational procedure was used to calculate, for all storms that had water-quality data, the percentage of constituent load entrainment in specified depths of runoff. The plot of percentage of constituent load entrained as a function of runoff is termed the percentage-entrainment curve. Percentage-entrainment curves were developed for three different source areas of basin runoff: (1) the hydraulically effective impervious area, (2) the contributing area, and (3) the drainage area. With basin runoff expressed in inches over the contributing area, the depth of runoff required to remove 90 percent of the constituent load ranged from about 0.4 inch to about 1.4 inches; and to remove 80 percent, from about 0.3 to 0.9 inch. Analysis of variance, using depth of runoff from the contributing area as the response variable, showed that the factor 'basin' is statistically significant, but that the factor 'constituent' is not statistically significant in the forming of the percentage-entrainment curve. Evidently the sewerage design, whether elongated or concise in plan dictates the shape of the percentage-entrainment curve. The percentage-entrainment curves for all constituents were averaged for each basin and plotted against basin runoff for three source areas of runoff-the hydraulically effective impervious area, the contributing area, and the drainage area. The relative positions of the three curves are directly related to the relative sizes of the three source areas considered. One general percentage-entrainment curve based on runoff from the contributing area was formed by averaging across

  18. Fuel decomposition and boundary-layer combustion processes of hybrid rocket motors

    NASA Technical Reports Server (NTRS)

    Chiaverini, Martin J.; Harting, George C.; Lu, Yeu-Cherng; Kuo, Kenneth K.; Serin, Nadir; Johnson, David K.

    1995-01-01

    Using a high-pressure, two-dimensional hybrid motor, an experimental investigation was conducted on fundamental processes involved in hybrid rocket combustion. HTPB (Hydroxyl-terminated Polybutadiene) fuel cross-linked with diisocyanate was burned with GOX under various operating conditions. Large-amplitude pressure oscillations were encountered in earlier test runs. After identifying the source of instability and decoupling the GOX feed-line system and combustion chamber, the pressure oscillations were drastically reduced from +/-20% of the localized mean pressure to an acceptable range of +/-1.5% Embedded fine-wire thermocouples indicated that the surface temperature of the burning fuel was around 1000 K depending upon axial locations and operating conditions. Also, except near the leading-edge region, the subsurface thermal wave profiles in the upstream locations are thicker than those in the downstream locations since the solid-fuel regression rate, in general, increases with distance along the fuel slab. The recovered solid fuel slabs in the laminar portion of the boundary layer exhibited smooth surfaces, indicating the existence of a liquid melt layer on the burning fuel surface in the upstream region. After the transition section, which displayed distinct transverse striations, the surface roughness pattern became quite random and very pronounced in the downstream turbulent boundary-layer region. Both real-time X-ray radiography and ultrasonic pulse-echo techniques were used to determine the instantaneous web thickness burned and instantaneous solid-fuel regression rates over certain portions of the fuel slabs. Globally averaged and axially dependent but time-averaged regression rates were also obtained and presented.

  19. Hot Isostatic Press Manufacturing Process Development for Fabrication of RERTR Monolithic Fuel Plates

    SciTech Connect

    Crapps, Justin M.; Clarke, Kester D.; Katz, Joel D.; Alexander, David J.; Aikin, Beverly; Vargas, Victor D.; Montalvo, Joel D.; Dombrowski, David E.; Mihaila, Bogdan

    2012-06-06

    We use experimentation and finite element modeling to study a Hot Isostatic Press (HIP) manufacturing process for U-10Mo Monolithic Fuel Plates. Finite element simulations are used to identify the material properties affecting the process and improve the process geometry. Accounting for the high temperature material properties and plasticity is important to obtain qualitative agreement between model and experimental results. The model allows us to improve the process geometry and provide guidance on selection of material and finish conditions for the process strongbacks. We conclude that the HIP can must be fully filled to provide uniform normal stress across the bonding interface.

  20. The effect of fuel processes on heavy duty automotive diesel engine emissions

    SciTech Connect

    Reynolds, E.G.

    1995-12-31

    The effect of fuel quality on exhaust emissions from 2 heavy duty diesel engines has been measured over the ECE R49 test cycle. The engines were selected to represent technologies used to meet Euro 1 and 2 emission standards (1992/93 and 1995/96); engines 1 and 2 respectively. The test fuels were prepared by a combination of processing, blending and additive treatment. When comparing the emissions from engines 1 and 2, using base line data generated on the CEC reference fuel RF73-T-90, engine technology had the major effect on emission levels. Engine 2 reduced both particulate matter (PM) and carbon monoxide levels by approximately 50%, with total hydrocarbon (THC) being approximately 75% lower. Oxides of nitrogen levels were similar for both engines. The variations in test fuel quality had marginal effects on emissions, with the two engines giving directionally opposite responses in some cases. For instance, there was an effect on CO and NOx but where one engine showed a reduction the other gave an increase. There were no significant changes in THC emissions from either engine when operating on any of the test fuels. When the reference fuel was hydrotreated, engine 1 showed a trend towards reduced particulate and NOx but with CO increasing. Engine 2 also showed a trend for reduced particulate levels, with an increase in NOx and no change in CO. Processing to reduce the final boiling point of the reference fuel showed a trend towards reduced particulate emissions with CO increasing on engine 1 but decreasing on engine 2.